Silicone prepolymer solutions

ABSTRACT

In one aspect, the invention relates to silicone prepolymer compositions comprising a silicone prepolymer and a solvent. A soluble silicone prepolymer can be provided having increased average silicon content, thereby attaining a desired oxygen permeability. A solvent can be provided with a desired balance between hydrophilicity and hydrophobicity by selection and modification of the solvent molecular structure, resulting in molded polymer films and articles that exhibit minimal or nonexistent eye irritation and exhibit highly transparent products. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present invention.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Application No. 61/017,158filed Dec. 27, 2007, which is hereby incorporated herein by reference inits entirety.

BACKGROUND

Contact lenses have been used commercially to improve vision since the1950s. Many current contact lenses are made of hydrogels formed bypolymerizing hydrophilic monomers such as hydroxyethylmethacrylate(HEMA) and vinylpyrrolidone in the presence of a minor amount of acrosslinking agent.

When producing continuous wear contact lenses, it can be advantageous toinclude silicone monomer in order to increase oxygen permeability in thelenses. However, as the amount of the silicone monomer in the reactivemixture is increased, dissolution with conventional solvent systemsbecomes more difficult and the resulting materials are typicallyhydrophobic.

In cases where non-aqueous solvents are used to dissolve hydrophobicmaterials, the solvent typically must be later removed by extraction orthe like. Thus, a step of replacing the solvent with water is frequentlyutilized. Additionally, while some solvents can adequately dissolvesilicone prepolymers, these solvents can irritate a contact lenswearer's eyes. Thus, complete removal of such a solvent becomesnecessary. Moreover, some solvents (e.g., poly(ethylene glycol)) showless irritation to a contact lens wearer's eyes and provide a uniformand transparent silicone prepolymer solution. However, when polymerfilms prepared in such solutions are immersed in water, they becomeopaque. That is, polymerizations in such solvents typically result inunclear polymer films.

Therefore, there remains a need for methods and compositions thatovercome these deficiencies and that effectively provide polymerizationcompositions wherein the monomers and/or prepolymers are soluble inwater-soluble solvents and result in molded polymer films and articlesexhibiting satisfactory oxygen permeability, minimal or nonexistent eyeirritation, and highly transparent products.

SUMMARY

As embodied and broadly described herein, the invention, in one aspect,relates to silicone prepolymer compositions comprising a siliconeprepolymer and a solvent.

In a further aspect, the invention relates to silicone prepolymercompositions comprising from about 20% to about 95% content by weight ofthe composition of a silicone prepolymer having an average siliconcontent of from about 10% to about 30% by weight of the prepolymer, andfrom about 5% to about 80% content by weight of the composition of asolvent.

In a further aspect, the invention relates to solvent compounds having astructure represented by formula (1s):R¹¹—O-G-R¹³,  (1s)

wherein R¹¹ and R¹³ independently represent hydrogen or an organicradical comprising from 1 to 20 carbon atoms; and wherein G comprises:at least one group having a structure represented by formula (1s1):

wherein the number of group(s) in G having a structure represented byformula (1s1) is defined as m=an integer of from 1 to 50; and at leastone group having a structure represented by formula (1s2):

wherein the number of group(s) in G having a structure represented byformula (1 s2) is defined as n=an integer of from 1 to 50, and whereinR¹² is a divalent organic radical comprising from 3 to 20 carbon atoms;and wherein m/(m+n) is from about 0.05 to about 0.95.

In a further aspect, the invention relates to solvent compounds having astructure represented by formula (2s):

wherein R²¹ to R²⁴ independently represent hydrogen or an organicradical comprising from 1 to 20 carbon atoms; wherein R²⁵ and R²⁶independently represent hydrogen or an organic radical comprising from 1to 20 carbon atoms; wherein n represent integers of from 1 to 50;wherein the number of carbon atom in R²⁵ and R²⁶ is defined as r; andwherein (n+1)/(2n+r) is not more than about 0.45.

In a further aspect, the invention relates to polymers produced bypolymerizing prepolymer from the disclosed compositions.

In a further aspect, the invention relates to ophthalmic lenses, e.g.,contact lenses, produced from the disclosed polymers.

In a further aspect, the invention relates to products of the disclosedmethods.

Additional advantages of the invention will be set forth in part in thedescription which follows, and in part will be obvious from thedescription, or may be learned by practice of the invention. Theadvantages of the invention will be realized and attained by means ofthe elements and combinations particularly pointed out in the appendedclaims. It is to be understood that both the foregoing generaldescription and the following detailed description are exemplary andexplanatory only and are not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF THE FIGURES

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate several embodiments and togetherwith the description illustrate the disclosed compositions and methods.

FIG. 1 shows a plot of R (1/Q) versus thickness (1 m).

FIG. 2 shows an apparatus for oxygen permeability measurement.

FIG. 3 shows the structure of an electrode unit used to measure oxygenpermeability.

FIG. 4 shows a schematic of an oxygen permeability measurement setup.

DETAILED DESCRIPTION

The present invention can be understood more readily by reference to thefollowing detailed description of the invention and the Examplesincluded therein.

Before the present compounds, compositions, articles, devices, and/ormethods are disclosed and described, it is to be understood that theyare not limited to specific synthetic methods unless otherwisespecified, or to particular reagents unless otherwise specified, as suchmay, of course, vary. It is also to be understood that the terminologyused herein is for the purpose of describing particular embodiments onlyand is not intended to be limiting. Although any methods and materialssimilar or equivalent to those described herein can be used in thepractice or testing of the present invention, example methods andmaterials are now described.

All publications mentioned herein are incorporated herein by referenceto disclose and describe the methods and/or materials in connection withwhich the publications are cited. The publications discussed herein areprovided solely for their disclosure prior to the filing date of thepresent application. Nothing herein is to be construed as an admissionthat the present invention is not entitled to antedate such publicationby virtue of prior invention. Further, the dates of publication providedherein may be different from the actual publication dates, which mayneed to be independently confirmed.

A. DEFINITIONS

As used in the specification and the appended claims, the singular forms“a,” “an” and “the” include plural referents unless the context clearlydictates otherwise. Thus, for example, reference to “a component,” “apolymer,” or “a residue” includes mixtures of two or more suchcomponents, polymers, or residues, and the like.

Ranges can be expressed herein as from “about” one particular value,and/or to “about” another particular value. When such a range isexpressed, another embodiment includes from the one particular valueand/or to the other particular value. Similarly, when values areexpressed as approximations, by use of the antecedent “about,” it willbe understood that the particular value forms another embodiment. Itwill be further understood that the endpoints of each of the ranges aresignificant both in relation to the other endpoint, and independently ofthe other endpoint. It is also understood that there are a number ofvalues disclosed herein, and that each value is also herein disclosed as“about” that particular value in addition to the value itself. Forexample, if the value “10” is disclosed, then “about 10” is alsodisclosed. It is also understood that each unit between two particularunits are also disclosed. For example, if 10 and 15 are disclosed, then11, 12, 13, and 14 are also disclosed.

As used herein, the term “residue” of a chemical species refers to themoiety that is the resulting product of the chemical species in aparticular reaction scheme or subsequent formulation or chemicalproduct, regardless of whether the moiety is actually obtained from thechemical species. Thus, an ethylene glycol residue in a polyester refersto one or more —OCH₂CH₂O— units in the polyester, regardless of whetherethylene glycol was used to prepare the polyester. Similarly, a sebacicacid residue in a polyester refers to one or more —CO(CH₂)₈CO— moietiesin the polyester, regardless of whether the residue is obtained byreacting sebacic acid or an ester thereof to obtain the polyester.

The term “organic residue” defines a carbon containing residue, i.e., aresidue comprising at least one carbon atom, and includes but is notlimited to the carbon-containing groups, residues, or radicals definedhereinabove. Organic residues can contain various heteroatoms, or bebonded to another molecule through a heteroatom, including oxygen,nitrogen, sulfur, phosphorus, or the like. Examples of organic residuesinclude but are not limited alkyl or substituted alkyls, alkoxy orsubstituted alkoxy, mono or di-substituted amino, amide groups, etc.Organic residues can preferably comprise 1 to 18 carbon atoms, 1 to 15,carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, 1 to 6 carbonatoms, or 1 to 4 carbon atoms. In a further aspect, an organic residuecan comprise 2 to 18 carbon atoms, 2 to 15, carbon atoms, 2 to 12 carbonatoms, 2 to 8 carbon atoms, 2 to 4 carbon atoms, or 2 to 4 carbon atoms

A very close synonym of the term “residue” is the term “radical,” whichas used in the specification and concluding claims, refers to afragment, group, or substructure of a molecule described herein,regardless of how the molecule is prepared. For example, a2,4-thiazolidinedione radical in a particular compound has the structure

regardless of whether thiazolidinedione is used to prepare the compound.In some embodiments the radical (for example an alkyl) can be furthermodified (i.e., substituted alkyl) by having bonded thereto one or more“substituent radicals.” The number of atoms in a given radical is notcritical to the present invention unless it is indicated to the contraryelsewhere herein.

“Organic radicals,” as the term is defined and used herein, contain oneor more carbon atoms. An organic radical can have, for example, 1-26carbon atoms, 1-18 carbon atoms, 1-12 carbon atoms, 1-8 carbon atoms,1-6 carbon atoms, or 1-4 carbon atoms. In a further aspect, an organicradical can have 2-26 carbon atoms, 2-18 carbon atoms, 2-12 carbonatoms, 2-8 carbon atoms, 2-6 carbon atoms, or 2-4 carbon atoms. Organicradicals often have hydrogen bound to at least some of the carbon atomsof the organic radical. One example, of an organic radical thatcomprises no inorganic atoms is a 5,6,7,8-tetrahydro-2-naphthyl radical.In some embodiments, an organic radical can contain 1-10 inorganicheteroatoms bound thereto or therein, including halogens, oxygen,sulfur, nitrogen, phosphorus, and the like. Examples of organic radicalsinclude but are not limited to an alkyl, substituted alkyl, cycloalkyl,substituted cycloalkyl, mono-substituted amino, di-substituted amino,acyloxy, cyano, carboxy, carboalkoxy, alkylcarboxamide, substitutedalkylcarboxamide, dialkylcarboxamide, substituted dialkylcarboxamide,alkylsulfonyl, alkylsulfinyl, thioalkyl, thiohaloalkyl, alkoxy,substituted alkoxy, haloalkyl, haloalkoxy, aryl, substituted aryl,heteroaryl, heterocyclic, or substituted heterocyclic radicals, whereinthe terms are defined elsewhere herein. A few non-limiting examples oforganic radicals that include heteroatoms include alkoxy radicals,trifluoromethoxy radicals, acetoxy radicals, dimethylamino radicals andthe like.

“Inorganic radicals,” as the term is defined and used herein, contain nocarbon atoms and therefore comprise only atoms other than carbon.Inorganic radicals comprise bonded combinations of atoms selected fromhydrogen, nitrogen, oxygen, silicon, phosphorus, sulfur, selenium, andhalogens such as fluorine, chlorine, bromine, and iodine, which can bepresent individually or bonded together in their chemically stablecombinations. Inorganic radicals have 10 or fewer, or preferably one tosix or one to four inorganic atoms as listed above bonded together.Examples of inorganic radicals include, but not limited to, amino,hydroxy, halogens, nitro, thiol, sulfate, phosphate, and like commonlyknown inorganic radicals. The inorganic radicals do not have bondedtherein the metallic elements of the periodic table (such as the alkalimetals, alkaline earth metals, transition metals, lanthanide metals, oractinide metals), although such metal ions can sometimes serve as apharmaceutically acceptable cation for anionic inorganic radicals suchas a sulfate, phosphate, or like anionic inorganic radical. Inorganicradicals do not comprise metalloids elements such as boron, aluminum,gallium, germanium, arsenic, tin, lead, or tellurium, or the noble gaselements, unless otherwise specifically indicated elsewhere herein.

As used herein, the terms “optional” or “optionally” means that thesubsequently described event or circumstance may or may not occur, andthat the description includes instances where said event or circumstanceoccurs and instances where it does not.

As used herein, the term “polymer” refers to a relatively high molecularweight organic compound, natural or synthetic, whose structure can berepresented by a repeated small unit, the monomer (e.g., polyethylene,rubber, cellulose). Synthetic polymers are typically formed by additionor condensation polymerization of monomers.

As used herein, the term “copolymer” refers to a polymer formed from twoor more different repeating units (monomer residues). By way of exampleand without limitation, a copolymer can be an alternating copolymer, arandom copolymer, a block copolymer, or a graft copolymer. It is alsocontemplated that, in certain aspects, various block segments of a blockcopolymer can themselves comprise copolymers.

As used herein, the term “oligomer” refers to a relatively low molecularweight polymer in which the number of repeating units is between two andten, for example, from two to eight, from two to six, or form two tofour. In one aspect, a collection of oligomers can have an averagenumber of repeating units of from about two to about ten, for example,from about two to about eight, from about two to about six, or formabout two to about four.

As used herein, the term “prepolymer” refers to a polymer of relativelylow molecular weight, usually intermediate between that of the monomerand the final polymer or resin, which may be mixed with compoundingadditives, and which is capable of being hardened by furtherpolymerization during or after a forming process.

As used herein, the term “molecular weight” (MW) refers to the mass ofone molecule of that substance, relative to the unified atomic mass unitu (equal to 1/12 the mass of one atom of carbon-12).

As used herein, the term “number average molecular weight” (M_(n))refers to the common, mean, average of the molecular weights of theindividual polymers. M_(n) can be determined by measuring the molecularweight of n polymer molecules, summing the weights, and dividing by n.M_(n) is calculated by:

${{\overset{\_}{M}}_{n} = \frac{\sum\limits_{i}{N_{i}M_{i}}}{\sum\limits_{i}N_{i}}},$wherein N_(i) is the number of molecules of molecular weight M_(i). Thenumber average molecular weight of a polymer can be determined by gelpermeation chromatography, viscometry (Mark-Houwink equation), lightscattering, analytical ultracentrifugation, vapor pressure osmometry,end-group titration, and colligative properties.

As used herein, the term “weight average molecular weight” (M_(w))refers to an alternative measure of the molecular weight of a polymer.M_(w) is calculated by:

${{\overset{\_}{M}}_{w} = \frac{\sum\limits_{i}{N_{i}M_{i}^{2}}}{\sum\limits_{i}{N_{i}M_{i}}}},$wherein N_(i) is the number of molecules of molecular weight M_(i).Intuitively, if the weight average molecular weight is w, and you pick arandom monomer, then the polymer it belongs to will have a weight of won average. The weight average molecular weight can be determined bylight scattering, small angle neutron scattering (SANS), X-rayscattering, and sedimentation velocity.

As used herein, the terms “polydispersity” and “polydispersity index”refer to the ratio of the weight average to the number average(M_(w)/M_(n)).

As used herein, the terms “initiator” and “radical initiator” refer tosubstances that can produce radical species under mild conditions andpromote radical polymerization reactions. These substances generallypossess bonds that have small bond dissociation energies. Examplesinclude halogen molecules, azo compounds, and organic peroxides.Chlorine, for example, gives two chlorine radicals (Cl.) by irradiationwith ultraviolet light. Azo compounds (R—N═N—R′) can be the precursor oftwo carbon-centered radicals (R. and R′.) and nitrogen gas upon heatingand/or by irradiation. For example, AIBN and ABCN yield isobutyronitrileand cyclohexanecarbonitrile radicals, respectively. Organic peroxideseach have a peroxide bond (—O—O—), which is readily cleaved to give twooxygen-centered radicals. For example, di-t(tertiary)-butylperoxide(tBuOOtBu) gives two t-butanoyl radicals (tBuO.) and the radicals becomemethyl radicals (CH₃.) with the loss of acetone. Benzoyl peroxide((PhCOO)₂) generates benzoyloxyl radicals (PhCOO.), each of which losescarbon dioxide to be converted into a phenyl radical (Ph.).

As used herein, the term “polar moiety” refers to a functional group orpart of a molecule bearing a polar group. A polar group is a functionalgroup in which the distribution of electrons is uneven, thereby enablingit to take part in electrostatic interactions. Suitable polar groupsinclude hydroxyl, amide, carboxyl, amino, carbonate, carbamate,sulfonamide, sulfonic, phosphonic, methoxyethyl, methoxyethoxyethyl,hydroxyethyl, and hydroxyethoxyethyl groups.

As used herein, the term “polar silicone-containing residue” refers to aresidue containing at least one silicone function and at least one polarmoiety.

As used herein, the terms “polymerizable moiety” and “polymerizableresidue” refer to a chemical functionality capable of undergoing apolymerization reaction or cross-linking reaction to form a highermolecular weight compound and/or a more highly cross-linked structure.Suitable examples include methacryloyloxy groups, acryloyloxy groups,methacryl amide groups, acryl amide groups, styryl groups, vinyl groups,vinyl carbonate groups, vinyl carbamate groups, allyl carbonate groups,or allyl carbamate groups.

As used herein, the term “siloxanyl” refers to a structure having atleast one Si—O—Si bond. Thus, for example, siloxanyl group means a grouphaving at least one Si—O—Si group, and siloxanyl compound means acompound having at least one Si—O—Si group.

As used herein, the term “siloxanyl monomer” refers to a siloxanylcompound having at least one polymerizable carbon-carbon unsaturatedbond. In one aspect, the polymerizable carbon-carbon unsaturated bondcan be part of an alkylacryloyl moiety (e.g., acryloyl or a methacryloylmoiety).

As used herein, the term “substituted” is contemplated to include allpermissible substituents of organic compounds. In a broad aspect, thepermissible substituents include acyclic and cyclic, branched andunbranched, carbocyclic and heterocyclic, and aromatic and nonaromaticsubstituents of organic compounds. Illustrative substituents include,for example, those described below. The permissible substituents can beone or more and the same or different for appropriate organic compounds.For purposes of this disclosure, the heteroatoms, such as nitrogen, canhave hydrogen substituents and/or any permissible substituents oforganic compounds described herein which satisfy the valences of theheteroatoms. Unless explicitly disclosed, this disclosure is notintended to be limited in any manner by the permissible substituents oforganic compounds. Also, the terms “substitution” or “substituted with”include the implicit proviso that such substitution is in accordancewith permitted valence of the substituted atom and the substituent, andthat the substitution results in a stable compound, e.g., a compoundthat does not spontaneously undergo transformation such as byrearrangement, cyclization, elimination, etc.

As used herein, the term “optionally substituted” includes bothsubstituted and unsubstituted variations of the subject compound, group,radical, residue, or moiety. That is, in one aspect, the subjectcompound, group, radical, residue, or moiety can be substituted. In afurther aspect, the subject compound, group, radical, residue, or moietycan be unsubstituted.

In defining various terms, “A¹,” “A²,” “A³”, and “A⁴” are used herein asgeneric symbols to represent various specific substituents. Thesesymbols can be any substituent, not limited to those disclosed herein,and when they are defined to be certain substituents in one instance,they can, in another instance, be defined as some other substituents.

The term “alkyl” as used herein is a branched or unbranched saturatedhydrocarbon group of 1 to 24 carbon atoms, for example 1 to 12 carbonatoms or 1 to 6 carbon atoms, such as methyl, ethyl, n-propyl,isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl,s-pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl,tetradecyl, hexadecyl, eicosyl, tetracosyl, and the like. The alkylgroup can also be substituted or unsubstituted. The alkyl group can besubstituted with one or more groups including, but not limited to,substituted or unsubstituted alkyl, cycloalkyl, alkoxy, alkenyl,cycloalkenyl, alkynyl, cycloalkynyl, aryl, heteroaryl, aldehyde, amino,carboxylic acid, ester, ether, halide, hydroxy, ketone, azide, nitro,silyl, sulfo-oxo, or thiol, as described herein. A “lower alkyl” groupis an alkyl group containing from one to six carbon atoms.

Throughout the specification “alkyl” is generally used to refer to bothunsubstituted alkyl groups and substituted alkyl groups; however,substituted alkyl groups are also specifically referred to herein byidentifying the specific substituent(s) on the alkyl group. For example,the term “halogenated alkyl” specifically refers to an alkyl group thatis substituted with one or more halide, e.g., fluorine, chlorine,bromine, or iodine. The term “alkoxyalkyl” specifically refers to analkyl group that is substituted with one or more alkoxy groups, asdescribed below. The term “alkylamino” specifically refers to an alkylgroup that is substituted with one or more amino groups, as describedbelow, and the like. When “alkyl” is used in one instance and a specificterm such as “alkylalcohol” is used in another, it is not meant to implythat the term “alkyl” does not also refer to specific terms such as“alkylalcohol” and the like.

This practice is also used for other groups described herein. That is,while a term such as “cycloalkyl” refers to both unsubstituted andsubstituted cycloalkyl moieties, the substituted moieties can, inaddition, be specifically identified herein; for example, a particularsubstituted cycloalkyl can be referred to as, e.g., an“alkylcycloalkyl.” Similarly, a substituted alkoxy can be specificallyreferred to as, e.g., a “halogenated alkoxy,” a particular substitutedalkenyl can be, e.g., an “alkenylalcohol,” and the like. Again, thepractice of using a general term, such as “cycloalkyl,” and a specificterm, such as “alkylcycloalkyl,” is not meant to imply that the generalterm does not also include the specific term.

The term “cycloalkyl” as used herein is a non-aromatic carbon-based ringcomposed of at least three carbon atoms. Examples of cycloalkyl groupsinclude, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl,cyclohexyl, norbornyl, and the like. The term “heterocycloalkyl” is atype of cycloalkyl group as defined above, and is included within themeaning of the term “cycloalkyl,” where at least one of the carbon atomsof the ring is replaced with a heteroatom such as, but not limited to,nitrogen, oxygen, sulfur, or phosphorus. The cycloalkyl group andheterocycloalkyl group can be substituted or unsubstituted. Thecycloalkyl group and heterocycloalkyl group can be substituted with oneor more groups including, but not limited to, substituted orunsubstituted alkyl, cycloalkyl, alkoxy, alkenyl, cycloalkenyl, alkynyl,cycloalkynyl, aryl, heteroaryl, aldehyde, amino, carboxylic acid, ester,ether, halide, hydroxy, ketone, azide, nitro, silyl, sulfo-oxo, or thiolas described herein.

The term “polyalkylene group” as used herein is a group having two ormore CH₂ groups linked to one another. The polyalkylene group can berepresented by the formula —(CH₂)_(a)—, where “a” is an integer of from2 to 500.

The terms “alkoxy” and “alkoxyl” as used herein refer to an alkyl orcycloalkyl group bonded through an ether linkage; that is, an “alkoxy”group can be defined as —OA¹ where A¹ is alkyl or cycloalkyl as definedabove. “Alkoxy” also includes polymers of alkoxy groups as justdescribed; that is, an alkoxy can be a polyether such as —OA¹-OA² or—OA¹-(OA²)_(a)—OA³, where “a” is an integer of from 1 to 200 and A¹, A²,and A³ are alkyl and/or cycloalkyl groups.

The term “alkenyl” as used herein is a hydrocarbon group of from 2 to 24carbon atoms with a structural formula containing at least onecarbon-carbon double bond. Asymmetric structures such as (A¹A²)C═C(A³A⁴)are intended to include both the E and Z isomers. This may be presumedin structural formulae herein wherein an asymmetric alkene is present,or it may be explicitly indicated by the bond symbol C═C. The alkenylgroup can be substituted with one or more groups including, but notlimited to, substituted or unsubstituted alkyl, cycloalkyl, alkoxy,alkenyl, cycloalkenyl, alkynyl, cycloalkynyl, aryl, heteroaryl,aldehyde, amino, carboxylic acid, ester, ether, halide, hydroxy, ketone,azide, nitro, silyl, sulfo-oxo, or thiol, as described herein.

The term “cycloalkenyl” as used herein is a non-aromatic carbon-basedring composed of at least three carbon atoms and containing at least onecarbon-carbon double bound, i.e., C═C. Examples of cycloalkenyl groupsinclude, but are not limited to, cyclopropenyl, cyclobutenyl,cyclopentenyl, cyclopentadienyl, cyclohexenyl, cyclohexadienyl,norbornenyl, and the like. The term “heterocycloalkenyl” is a type ofcycloalkenyl group as defined above, and is included within the meaningof the term “cycloalkenyl,” where at least one of the carbon atoms ofthe ring is replaced with a heteroatom such as, but not limited to,nitrogen, oxygen, sulfur, or phosphorus. The cycloalkenyl group andheterocycloalkenyl group can be substituted or unsubstituted. Thecycloalkenyl group and heterocycloalkenyl group can be substituted withone or more groups including, but not limited to, substituted orunsubstituted alkyl, cycloalkyl, alkoxy, alkenyl, cycloalkenyl, alkynyl,cycloalkynyl, aryl, heteroaryl, aldehyde, amino, carboxylic acid, ester,ether, halide, hydroxy, ketone, azide, nitro, silyl, sulfo-oxo, or thiolas described herein.

The term “alkynyl” as used herein is a hydrocarbon group of 2 to 24carbon atoms with a structural formula containing at least onecarbon-carbon triple bond. The alkynyl group can be unsubstituted orsubstituted with one or more groups including, but not limited to,substituted or unsubstituted alkyl, cycloalkyl, alkoxy, alkenyl,cycloalkenyl, alkynyl, cycloalkynyl, aryl, heteroaryl, aldehyde, amino,carboxylic acid, ester, ether, halide, hydroxy, ketone, azide, nitro,silyl, sulfo-oxo, or thiol, as described herein.

The term “cycloalkynyl” as used herein is a non-aromatic carbon-basedring composed of at least seven carbon atoms and containing at least onecarbon-carbon triple bound. Examples of cycloalkynyl groups include, butare not limited to, cycloheptenyl, cyclooctynyl, cyclononenyl, and thelike. The term “heterocycloalkynyl” is a type of cycloalkenyl group asdefined above, and is included within the meaning of the term“cycloalkynyl,” where at least one of the carbon atoms of the ring isreplaced with a heteroatom such as, but not limited to, nitrogen,oxygen, sulfur, or phosphorus. The cycloalkynyl group andheterocycloalkynyl group can be substituted or unsubstituted. Thecycloalkynyl group and heterocycloalkynyl group can be substituted withone or more groups including, but not limited to, substituted orunsubstituted alkyl, cycloalkyl, alkoxy, alkenyl, cycloalkenyl, alkynyl,cycloalkynyl, aryl, heteroaryl, aldehyde, amino, carboxylic acid, ester,ether, halide, hydroxy, ketone, azide, nitro, silyl, sulfo-oxo, or thiolas described herein.

The term “aryl” as used herein is a group that contains any carbon-basedaromatic group including, but not limited to, benzene, naphthalene,phenyl, biphenyl, phenoxybenzene, and the like. The term “aryl” alsoincludes “heteroaryl,” which is defined as a group that contains anaromatic group that has at least one heteroatom incorporated within thering of the aromatic group. Examples of heteroatoms include, but are notlimited to, nitrogen, oxygen, sulfur, and phosphorus. Likewise, the term“non-heteroaryl,” which is also included in the term “aryl,” defines agroup that contains an aromatic group that does not contain aheteroatom. The aryl group can be substituted or unsubstituted. The arylgroup can be substituted with one or more groups including, but notlimited to, substituted or unsubstituted alkyl, cycloalkyl, alkoxy,alkenyl, cycloalkenyl, alkynyl, cycloalkynyl, aryl, heteroaryl,aldehyde, amino, carboxylic acid, ester, ether, halide, hydroxy, ketone,azide, nitro, silyl, sulfo-oxo, or thiol as described herein. The term“biaryl” is a specific type of aryl group and is included in thedefinition of “aryl.” Biaryl refers to two aryl groups that are boundtogether via a fused ring structure, as in naphthalene, or are attachedvia one or more carbon-carbon bonds, as in biphenyl.

The term “aldehyde” as used herein is represented by the formula —C(O)H.Throughout this specification “C(O)” is a short hand notation for acarbonyl group, i.e., C═O.

The terms “amine” or “amino” as used herein are represented by theformula NA¹A²A³, where A¹, A², and A³ can be, independently, hydrogen orsubstituted or unsubstituted alkyl, cycloalkyl, alkenyl, cycloalkenyl,alkynyl, cycloalkynyl, aryl, or heteroaryl group as described herein.

The term “carboxylic acid” as used herein is represented by the formula—C(O)OH.

The term “ester” as used herein is represented by the formula —OC(O)A¹or —C(O)OA¹, where A¹ can be a substituted or unsubstituted alkyl,cycloalkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkynyl, aryl, orheteroaryl group as described herein. The term “polyester” as usedherein is represented by the formula -(A¹O(O)C-A²-C(O)O)_(a)— or-(A¹O(O)C-A²-OC(O))_(a)—, where A¹ and A² can be, independently, asubstituted or unsubstituted alkyl, cycloalkyl, alkenyl, cycloalkenyl,alkynyl, cycloalkynyl, aryl, or heteroaryl group described herein and“a” is an integer from 1 to 500. “Polyester” is the term used todescribe a group that is produced by the reaction between a compoundhaving at least two carboxylic acid groups with a compound having atleast two hydroxyl groups.

The term “ether” as used herein is represented by the formula A¹OA²,where A¹ and A² can be, independently, a substituted or unsubstitutedalkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkynyl, aryl,or heteroaryl group described herein. The term “polyether” as usedherein is represented by the formula -(A¹O-A²O)_(a)—, where A¹ and A²can be, independently, a substituted or unsubstituted alkyl, cycloalkyl,alkenyl, cycloalkenyl, alkynyl, cycloalkynyl, aryl, or heteroaryl groupdescribed herein and “a” is an integer of from 1 to 500. Examples ofpolyether groups include polyethylene oxide, polypropylene oxide, andpolybutylene oxide.

The terms “halide” and “halo” as used herein refer to the halogensfluorine, chlorine, bromine, and iodine.

The terms “hydroxy” and “hydroxyl” as used herein is represented by theformula —OH.

The term “ketone” and “keto” as used herein is represented by theformula A¹C(O)A², where A¹ and A² can be, independently, a substitutedor unsubstituted alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl,cycloalkynyl, aryl, or heteroaryl group as described herein.

The term “azide” as used herein is represented by the formula —N₃. Theterm “nitro” as used herein is represented by the formula —NO₂.

The terms “nitrile” and “cyano” as used herein are represented by theformula —CN.

The term “silyl” as used herein is represented by the formula —SiA¹A²A³,where A¹, A², and A³ can be, independently, hydrogen or a substituted orunsubstituted alkyl, cycloalkyl, alkoxy, alkenyl, cycloalkenyl, alkynyl,cycloalkynyl, aryl, or heteroaryl group as described herein.

The term “sulfo-oxo” as used herein is represented by the formulas—S(O)A¹, —S(O)₂A¹, —OS(O)₂A¹, or —OS(O)₂OA¹, where A¹ can be hydrogen ora substituted or unsubstituted alkyl, cycloalkyl, alkenyl, cycloalkenyl,alkynyl, cycloalkynyl, aryl, or heteroaryl group as described herein.Throughout this specification “S(O)” is a short hand notation for S═O.The term “sulfonyl” is used herein to refer to the sulfo-oxo grouprepresented by the formula —S(O)₂A¹, where A¹ can be hydrogen or asubstituted or unsubstituted alkyl, cycloalkyl, alkenyl, cycloalkenyl,alkynyl, cycloalkynyl, aryl, or heteroaryl group as described herein.The term “sulfone” as used herein is represented by the formulaA¹S(O)₂A², where A¹ and A² can be, independently, a substituted orunsubstituted alkyl, cycloalkyl, alkenyl, cycloalkenyl, alkynyl,cycloalkynyl, aryl, or heteroaryl group as described herein. The term“sulfoxide” as used herein is represented by the formula A¹S(O)A², whereA¹ and A² can be, independently, a substituted or unsubstituted alkyl,cycloalkyl, alkenyl, cycloalkenyl, alkynyl, cycloalkynyl, aryl, orheteroaryl group as described herein.

The term “thiol” as used herein is represented by the formula —SH.

Unless stated to the contrary, a formula with chemical bonds shown onlyas solid lines and not as wedges or dashed lines contemplates eachpossible isomer, e.g., each enantiomer and diastereomer, and a mixtureof isomers, such as a racemic or scalemic mixture.

Disclosed are the components to be used to prepare the compositions ofthe invention as well as the compositions themselves to be used withinthe methods disclosed herein. These and other materials are disclosedherein, and it is understood that when combinations, subsets,interactions, groups, etc. of these materials are disclosed that whilespecific reference of each various individual and collectivecombinations and permutation of these compounds may not be explicitlydisclosed, each is specifically contemplated and described herein. Forexample, if a particular compound is disclosed and discussed and anumber of modifications that can be made to a number of moleculesincluding the compounds are discussed, specifically contemplated is eachand every combination and permutation of the compound and themodifications that are possible unless specifically indicated to thecontrary. Thus, if a class of molecules A, B, and C are disclosed aswell as a class of molecules D, E, and F and an example of a combinationmolecule, A-D is disclosed, then even if each is not individuallyrecited each is individually and collectively contemplated meaningcombinations, A-E, A-F, B-D, B-E, B-F, C-D, C-E, and C—F are considereddisclosed. Likewise, any subset or combination of these is alsodisclosed. Thus, for example, the sub-group of A-E, B-F, and C-E wouldbe considered disclosed. This concept applies to all aspects of thisapplication including, but not limited to, steps in methods of makingand using the compositions of the invention. Thus, if there are avariety of additional steps that can be performed it is understood thateach of these additional steps can be performed with any specificembodiment or combination of embodiments of the methods of theinvention.

It is understood that the compositions disclosed herein have certainfunctions. Disclosed herein are certain structural requirements forperforming the disclosed functions, and it is understood that there area variety of structures that can perform the same function that arerelated to the disclosed structures, and that these structures willtypically achieve the same result.

B. SILICONE PREPOLYMER COMPOSITIONS

In the preparation of silicone polymers, the use of prepolymers asstarting materials can inhibit shrinkage during the polymerization stepas well as eliminate the need to extract residual monomer. In theformation of contact lenses from silicone polymers, it can be desirableto increase the silicon content of the prepolymer in order to obtainsufficient oxygen permeability in the resulting polymer; however, it canbe difficult to dissolve such prepolymers in water-soluble solvents.

Some non-aqueous solvents can be used to dissolve such siliconeprepolymers; however, these can irritate eyes. Thus, subsequent removalof the non-aqueous solvent and replacement with water can becomenecessary. Some water-soluble solvents (e.g., poly(ethylene glycol))show less irritation to eyes and can provide uniform silicone prepolymersolutions. However, polymer films made by polymerizing siliconeprepolymer-poly(ethylene glycol) solutions become opaque when the filmsare immersed in water.

In contrast, the disclosed silicone prepolymer compositions compriseincreased silicon content prepolymers in uniform, transparent solutionssuitable as starting materials for polymerization. Moreover, polymersproduced from these silicone prepolymer compositions provideeye-friendly, transparent films for use as ophthalmic lenses, includingcontact lenses, intraocular lenses, artificial cornea, and the like.

C. COMPOSITIONS

In one aspect, the invention relates to a silicone prepolymercomposition comprising from about 20% to about 95% content by weight ofthe composition of a silicone prepolymer having an average siliconcontent of from about 10% to about 30% by weight of the prepolymer, andfrom about 5% to about 80% content by weight of the composition of asolvent.

In one aspect, the solvent is a compound having a structure representedby formula (1s):R¹¹—O-G-R¹³,  (1s)wherein R¹¹ and R¹³ independently represent hydrogen or an organicradical comprising from 1 to 20 carbon atoms; and wherein G comprises atleast one group having a structure represented by formula (1s1):

wherein the number of group(s) in G having a structure represented byformula (1s1) is defined as m=an integer of from 1 to 50; and at leastone group having a structure represented by formula (1 s2):

wherein the number of group(s) in G having a structure represented byformula (1 s2) is defined as n=an integer of from 1 to 50, and whereinR¹² is a divalent organic radical comprising from 3 to 20 carbon atoms;wherein m and n independently represent integers of from 0 to 50, andwherein m/(m+n) is from about 0.05 to about 0.95.

In one aspect, the solvent is a compound having a structure representedby formula

wherein R²¹ to R²⁴ independently represent hydrogen or an organicradical comprising from 1 to 20 carbon atoms; wherein R²⁵ and R²⁶independently represent hydrogen or an organic radical comprising from 1to 20 carbon atoms; wherein n represent integers of from 1 to 50;wherein the number of carbon atom in R²⁵ and R²⁶ is defined as r; andwherein (n+1)/(2n+r) is not more than about 0.45.

In a further aspect, the invention relates to a silicone prepolymercomposition comprising from about 20% to about 95% content by weight ofthe composition of a silicone prepolymer having an average siliconcontent of from about 10% to about 30% by weight of the prepolymer, andfrom about 5% to about 80% content by weight of the composition of asolvent selected from a compound having a structure represented byformula (1s):R¹¹—O-G-R¹³,  (1s)wherein R¹¹ and R¹³ independently represent hydrogen or an organicradical comprising from 1 to 20 carbon atoms; and wherein G comprises atleast one group having a structure represented by formula (1s1):

wherein the number of group(s) in G having a structure represented byformula (1s1) is defined as m=an integer of from 1 to 50; and at leastone group having a structure represented by formula (1 s2):

wherein the number of group(s) in G having a structure represented byformula (1 s2) is defined as n=an integer of from 1 to 50, and whereinR¹² is a divalent organic radical comprising from 3 to 20 carbon atoms;wherein m and n independently represent integers of from 0 to 50, andwherein m/(m+n) is from about 0.05 to about 0.95; or a compound having astructure represented by formula (2s):

wherein R²¹ to R²⁴ independently represent hydrogen or an organicradical comprising from 1 to 20 carbon atoms; wherein R²⁵ and R²⁶independently represent hydrogen or an organic radical comprising from 1to 20 carbon atoms; wherein n represent integers of from 1 to 50;wherein the number of carbon atom in R²⁵ and R²⁶ is defined as r; andwherein (n+1)/(2n+r) is not more than about 0.45.

It is contemplated that mixtures of the two solvents can also be used.That is, in one aspect, the invention relates to a silicone prepolymercomposition comprising from about 20% to about 95% content by weight ofthe composition of a silicone prepolymer having an average siliconcontent of from about 10% to about 30% by weight of the prepolymer, andfrom about 5% to about 80% content by weight of the composition of asolvent mixture comprising a compound having a structure represented byformula (1s):R¹¹—O-G-R¹³,  (1s)wherein R¹¹ and R¹³ independently represent hydrogen or an organicradical comprising from 1 to 20 carbon atoms; and wherein G comprises atleast one group having a structure represented by formula (1s1):

wherein the number of group(s) in G having a structure represented byformula (1s1) is defined as m=an integer of from 1 to 50; and at leastone group having a structure represented by formula (1 s2):

wherein the number of group(s) in G having a structure represented byformula (1 s2) is defined as n=an integer of from 1 to 50, and whereinR¹² is a divalent organic radical comprising from 3 to 20 carbon atoms;wherein m and n independently represent integers of from 0 to 50, andwherein m/(m+n) is from about 0.05 to about 0.95; and a compound havinga structure represented by formula

wherein R²¹ to R²⁴ independently represent hydrogen or an organicradical comprising from 1 to 20 carbon atoms; wherein R²⁵ and R²⁶independently represent hydrogen or an organic radical comprising from 1to 20 carbon atoms; wherein n represent integers of from 1 to 50;wherein the number of carbon atom in R²⁵ and R²⁶ is defined as r; andwherein (n+1)/(2n+r) is not more than about 0.45. In various aspects,the solvent having a structure represented by formula (1s) can bepresent in the solvent mixture as from about 5% to about 95% by weightof the total solvent. For example, the solvent having a structurerepresented by formula (1s) can be present at from about 10% to about90%, from about 20% to about 80%, from about 30% to about 70%, fromabout 40% to about 60%, or about 50% of the total solvent mixture. Invarious aspects, the solvent having a structure represented by formula(2s) can be present in the solvent mixture as from about 5% to about 95%by weight of the total solvent. For example, the solvent having astructure represented by formula (2s) can be present at from about 10%to about 90%, from about 20% to about 80%, from about 30% to about 70%,from about 40% to about 60%, or about 50% of the total solvent mixture.It is also contemplated that the solvent mixture can further comprise aco-solvent.

In a further aspect, the silicone prepolymer solution further comprisesan initiator, for example, 2,2′-azobis(2,4-dimethylvaleronitrile).

In a further aspect, the composition further comprises from about 1% toabout 20% content by weight of the composition of poly (vinylpyrolidone), for example, from about 1% to about 10%, from about 1% toabout 8%, from about 1% to about 5%, or from about 1% to about 3%.

D. SOLVENTS

Selection and use of an appropriate solvent in a silicone prepolymercomposition can facilitate solvation of monomers and/or prepolymers.Further, selection and use of an appropriate solvent in a siliconeprepolymer composition can provide water-soluble solvents. Even further,selection and use of an appropriate solvent in a silicone prepolymercomposition can result in molded polymer films and articles that exhibitminimal or nonexistent eye irritation, and exhibit highly transparentproducts.

Without wishing to be bound by theory, it is believed that thetransparency of the resulting molded product is related to the balancebetween hydrophilicity and hydrophobicity in the solvent selected. Incertain aspects, a solvent can be provided with a desired balancebetween hydrophilicity and hydrophobicity by selection and modificationof the structure in the backbone of the solvent molecules (e.g.,variable organic residue solvents) and/or by selection and modificationof the structure at the ends of the solvent molecules (e.g., variableorganic endgroup solvents).

It is also contemplated that balance between hydrophilicity andhydrophobicity in the solvent can be achieved by selection andmodification of the structure in the backbone of the solvent molecules(e.g., variable organic residue) and by selection and modification ofthe structure at the ends of the solvent molecules (e.g., variableorganic endgroup) in the same solvent molecule. It is also contemplatedthat balance between hydrophilicity and hydrophobicity in the solventcan be achieved by selection and modification of the structure in thebackbone of the solvent molecules (e.g., variable organic residuesolvents) and by selection and modification of the structure at the endsof the solvent molecules (e.g., variable organic endgroup solvents) indifferent solvent molecules in the same solvent mixture.

1. Variable Organic Residue Solvents

In one aspect, a solvent can be provided with a desired balance betweenhydrophilicity and hydrophobicity by selection and modification of thestructure in the backbone of the solvent molecules.

a. Structure

In one aspect, the solvent is a compound having a structure representedby formula (1s):R¹¹—O-G-R¹³  (1s)wherein R¹¹ and R¹³ independently represent hydrogen or an organicradical comprising from 1 to 20 carbon atoms; and wherein G comprises atleast one group having a structure represented by formula (1s1):

wherein the number of group(s) in G having a structure represented byformula (1s1) is defined as m=an integer of from 1 to 50; and at leastone group having a structure represented by formula (1 s2):

wherein the number of group(s) in G having a structure represented byformula (1 s2) is defined as n=an integer of from 1 to 50, and whereinR¹² is a divalent organic radical comprising from 3 to 20 carbon atoms;wherein m and n independently represent integers of from 0 to 50, andwherein m/(m+n) is from about 0.05 to about 0.95.

In one aspect, m can be an integer of from 1 to 50, from 1 to 30, from 1to 20, from 1 to 10, from 1 to 9, from 1 to 8, from 1 to 7, from 1 to 6,from 1 to 5, from 1 to 4, from 1 to 3, or from 1 to 2. It is understoodthat the m units need not be sequential units. That is, the polymericstructure can be, but need not be, blocky in nature.

In one aspect, n can be an integer of from 1 to 50, from 1 to 30, from 1to 20, from 1 to 10, from 1 to 9, from 1 to 8, from 1 to 7, from 1 to 6,from 1 to 5, from 1 to 4, from 1 to 3, or from 1 to 2. It is understoodthat the n units need not be sequential units. That is, the polymericstructure can be, but need not be, blocky in nature.

In one aspect, m/(m+n) can be from about 0.05 to about 0.95, from about0.1 to about 0.9, from about 0.15 to about 0.85, from about 0.2 to about0.8, from about 0.25 to about 0.75, from about 0.3 to about 0.7, fromabout 0.35 to about 0.65, from about 0.4 to about 0.6, from about 0.45to about 0.55, or about 0.5. In a further aspect, m/(m+n) can be fromabout 0.05 to about 0.5 or from about 0.5 to about 0.95.

In one aspect, R¹¹ and R¹³ independently represent hydrogen, a C₁-C₂₀alkyl residue, or a C₁-C₂₀ aryl residue. In a further aspect, both R¹¹and R¹³ are hydrogen. In a further aspect, one of R¹¹ and R¹³ ishydrogen and the other is a C₁-C₂₀ alkyl residue or a C₁-C₂₀ arylresidue. In a further aspect, one of R¹¹ and R¹³ represents hydrogen andthe other of R¹¹ and R¹³ represents a C₁-C₁₀ alkyl residue or a C₁-C₁₀aryl residue. In a further aspect, one or both of R¹¹ and R¹³ representa C₁-C₂₀ alkyl residue, for example, a C₁-C₁₆ alkyl residue, C₁-C₁₂alkyl residue, C₁-C₁₀ alkyl residue, C₁-C₈ alkyl residue, C₁-C₆ alkylresidue, or C₁-C₄ alkyl residue. For example, each of R¹¹ and R¹³ canindependently comprise methyl, ethyl, n-propyl, isopropyl, n-butyl,isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, s-pentyl, neopentyl,hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tetradecyl, or hexadecyl.It is understood that each R¹¹ and R¹³ can be independently substitutedor unsubstituted, linear or cyclic, and branched or unbranched.

In a further aspect, one or both of R¹¹ and R¹³ represent a C₁-C₂₀ arylresidue, for example, a C₁-C₁₆ aryl residue, C₁-C₁₂ aryl residue, C₁-C₁₀aryl residue, C₁-C₈ aryl residue, or C₁-C₆ aryl residue. For example,each of R¹¹ and R¹³ can independently comprise benzyl, phenyl, naphthyl,biphenyl, thiophenyl, pyrrolyl, furanyl, or pyridinyl. It is understoodthat each R¹¹ and R¹³ can be independently substituted or unsubstituted,linear or cyclic, and branched or unbranched. In a further aspect, oneof R¹¹ and R¹³ is a C₁-C₂₀ alkyl residue and the other is a C₁-C₂₀ arylresidue. In a further aspect, R¹¹ and R¹³ can be selected to be a C₁-C₂₀alkylsilyl (e.g., trimethylsilyl or t-butyldimethylsilyl) group.

In one aspect, the ethylene oxide residue(s) and —R¹²—O— group(s) in thesolvent represented by the formula (s) are randomly copolymerized.

In one aspect, R¹² comprises a divalent organic radical comprising from3 to 20 carbon atoms, for example, from 3 to 16 carbon atoms, from 3 to12 carbon atoms, from 3 to 10 carbon atoms, from 3 to 8 carbon atoms,from 3 to 6 carbon atoms, 4 carbon atoms, or 3 carbon atoms. In oneaspect, R¹² is a residue of propylene oxide, butylene oxide, ortrimethylene oxide. In a further aspect, R¹² represents a C₃-C₂₀alkylene residue or a C₃-C₂₀ arylene residue.

In one aspect, the solvent has a structure represented by formula (1s),and R¹² has a structure represented by formula (1s2-1):

wherein R¹⁴ represents a C₁-C₁₈ alkyl residue or a C₁-C₁₈ aryl residue.For example, R¹⁴ can be an optionally substituted C₁-C₁₈ alkyl or arylresidue, an optionally substituted C₁-C₁₆ alkyl or aryl residue, anoptionally substituted C₁-C₁₂ alkyl or aryl residue, an optionallysubstituted C₁-C₁₀ alkyl or aryl residue, an optionally substitutedC₁-C₈ alkyl or aryl residue, an optionally substituted C₁-C₆ alkyl oraryl residue, or an optionally substituted C₁-C₄ alkyl or aryl residue.In a further aspect, R¹⁴ can be methyl, ethyl, n-propyl, isopropyl,n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, s-pentyl,neopentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tetradecyl, orhexadecyl.

In one aspect, the ratio of oxygen atom to carbon atom in the formula(1s) is not more than 0.37. For example, (the number of oxygenatom)/(the number of carbon atom) can be less than about 0.35, less thanabout 0.30, less than about 0.25, less than about 0.20, less than about0.15, or less than about 0.10.

In a further aspect, the number average molecular weight of the solventis not more than 450, not more than 425, not more than 400, not morethan 375, not more than 350, not more than 325, or not more than 300.

In a further aspect, the solvent comprises one or more additionalcomonomers.

In one aspect, the solvent comprises a poly(ethylene glycol/propyleneglycol) [poly(EG+PG)] random copolymer, (50:50) mono(n-butyl)ether.

It is understood that any one or more of the disclosed aspects,examples, or species can optionally be excluded from the invention.

b. Methods of Making

In one aspect, the disclosed solvents can be obtained commercially orobtained from commercially available materials. One having ordinaryskill in the art will understand how to prepare the disclosed solvents.For example, the disclosed solvents can be prepared by known chemicalreactions such as copolymerization of oxiranes including ethylene oxideand substituted ethylene oxides (e.g., propylene oxide, butylene oxide)or ring-opening metathesis reactions.

In one aspect, many of the disclosed solvents can be prepared by thealkylation of ethylene oxide-based copolymers. As shown below,8,11,14-trimethyl-3,6,9,12,15-pentaoxaoctadecane-1,17-diol can bealkylated with, e.g., propyl bromide to provide5,8,11,14-tetramethyl-4,7,10,13,16,19,22-heptaoxapentacosane:

It is contemplated that more that one alkyl halide can be used in thesame reaction. It is also understood that more or less than one molarequivalent of the halide can be added and that reaction product (ormixture of reaction products) can be controlled by stoichiometry ofstarting materials.

In a further aspect, a poly(ethylene glycol/butylene glycol) copolymer,dialkyl ether can be prepared:

In a further aspect, a hybrid reaction scheme employing bothpolymerization and alkylation can be used:

It is understood that any one or more of the disclosed aspects,examples, or species can optionally be excluded from the invention.

2. Variable Organic Endgroup Solvents

In one aspect, a solvent can be provided with a desired balance betweenhydrophilicity and hydrophobicity by selection and modification of thestructure at the ends of the solvent molecules.

a. Structure

In one aspect, the solvent is a compound having a structure representedby formula (2s):

wherein R²¹ to R²⁴ independently represent hydrogen or an organicradical comprising from 1 to 20 carbon atoms; wherein R²⁵ and R²⁶independently represent hydrogen or an organic radical comprising from 1to 20 carbon atoms; wherein n represent integers of from 1 to 50;wherein the number of carbon atom in R²⁵ and R²⁶ is defined as r; andwherein (n+1)/(2n+r) is not more than about 0.45.

In one aspect, n can be an integer of from 1 to 50, from 1 to 30, from 1to 20, from 1 to 10, from 1 to 9, from 1 to 8, from 1 to 7, from 1 to 6,from 1 to 5, from 1 to 4, from 1 to 3, or from 1 to 2.

In one aspect, R²¹ to R²⁴ independently represent hydrogen, a C₁-C₂₀alkyl residue, or a C₁-C₂₀ aryl residue. In a further aspect, one ormore of R²¹ to R²⁴ represent a C₁-C₂₀ alkyl residue, for example, aC₁-C₁₆ alkyl residue, C₁-C₁₂ alkyl residue, C₁-C₁₀ alkyl residue, C₁-C₈alkyl residue, C₁-C₆ alkyl residue, or C₁-C₄ alkyl residue. For example,each of R²¹ to R²⁴ can independently comprise methyl, ethyl, n-propyl,isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl,s-pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl,tetradecyl, or hexadecyl. It is understood that each R²¹ to R²⁴ can beindependently substituted or unsubstituted, linear or cyclic, andbranched or unbranched. In a further aspect, two or more of R²¹ to R²⁴together form a ring structure

In one aspect, all of R²¹ to R²⁴ are hydrogen (i.e., ethylene glycolresidue). In a further aspect, three of R²¹ to R²⁴ are hydrogen and theother is C1 to C4 alkyl, for example, methyl, ethyl, propyl, or butyl(i.e., propylene glycol, butylene glycol, or higher glycol residue).

In one aspect, R²⁵ and R²⁶ independently represent hydrogen, a C₁-C₂₀alkyl residue, or a C₁-C₂₀ aryl residue. In a further aspect, one of R²⁵and R²⁶ is hydrogen and the other is a C₃-C₂₀ alkyl residue or a C₃-C₂₀aryl residue. In a further aspect, one of R²⁵ and R²⁶ representshydrogen and the other of R²⁵ and R²⁶ represents a C₃-C₁₀ alkyl residueor a C₃-C₁₀ aryl residue. In a further aspect, one or both of R²⁵ andR²⁶ represent a C₁-C₂₀ alkyl residue, for example, a C₁-C₁₆ alkylresidue, C₁-C₁₂ alkyl residue, C₁-C₁₀ alkyl residue, C₁-C₈ alkylresidue, C₁-C₆ alkyl residue, or C₁-C₄ alkyl residue. For example, eachof R²⁵ and R²⁶ can independently comprise methyl, ethyl, n-propyl,isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl,s-pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl,tetradecyl, or hexadecyl. It is understood that each R²⁵ and R²⁶ can beindependently substituted or unsubstituted, linear or cyclic, andbranched or unbranched.

In a further aspect, one or both of R²⁵ and R²⁶ represent a C₁-C₂₀ arylresidue, for example, a C₁-C₁₆ aryl residue, C₁-C₁₂ aryl residue, C₁-C₁₀aryl residue, C₁-C₈ aryl residue, or C₁-C₆ aryl residue. For example,each of R²⁵ and R²⁶ can independently comprise benzyl, phenyl, naphthyl,biphenyl, thiophenyl, pyrrolyl, furanyl, or pyridinyl. It is understoodthat each R²⁵ and R²⁶ can be independently substituted or unsubstituted,linear or cyclic, and branched or unbranched. In a further aspect, oneof R²⁵ and R²⁶ is a C₁-C₂₀ alkyl residue and the other is a C₁-C₂₀ arylresidue. In a further aspect, R²⁵ and R²⁶ can be selected to be a C₁-C₂₀alkylsilyl (e.g., trimethylsilyl or t-butyldimethylsilyl) group.

In a further aspect, the solvent has a structure represented by formula(2s), and wherein (n+1)/(2n+r) is not more than 0.40. For example, thesolvent can be selected so that (n+1)/(2n+r) is not more than 0.38, notmore than 0.35, not more than 0.32, not more than 0.30, not more than0.25, or not more than 0.20. The minimum total number of carbons for R²⁵and R²⁶, and the corresponding (n+1)/(2n+r), for various n is tabulatedbelow:

TABLE 1 minimum total carbons N for R²⁵ + R²⁶ (n + 1)/(2n + r) 1 3 0.4 24 0.375 3 4 0.4 4 4 0.416666667 5 4 0.428571429 6 5 0.411764706 7 50.421052632 8 5 0.428571429 9 5 0.434782609 10 5 0.44 12 6 0.43333333316 7 0.435897436 20 8 0.4375 24 9 0.438596491 30 10 0.442857143 40 120.445652174 50 14 0.447368421

In a further aspect, the number average molecular weight of the solventis not more than 450, not more than 425, not more than 400, not morethan 375, not more than 350, not more than 325, or not more than 300.

In a further aspect, the solvent comprises one or more additionalcomonomers.

In one aspect, the solvent comprises one or more of ethylene glycol monon-butyl ether, ethylene glycol mono n-hexyl ether, diethylene glycolmono n-butyl ether, diethylene glycol mono n-hexyl ether, triethyleneglycol mono n-butyl ether, or triethylene glycol mono i-propyl ether.

It is understood that any one or more of the disclosed aspects,examples, or species can optionally be excluded from the invention.

b. Methods of Making

In one aspect, the disclosed solvents can be obtained commercially orobtained from commercially available materials. One having ordinaryskill in the art will understand how to prepare the disclosed solvents.

In one aspect, many of the disclosed solvents can be prepared by thealkylation of alkylene oxide-based copolymers. As shown below,2,5,8,11,14-pentamethyl-3,6,9,12,15-pentaoxaoctadecane-1,17-diol can bealkylated with, e.g., propyl bromide to provide5,8,11,14,17,20-hexamethyl-4,7,10,13,16,19,22-heptaoxapentacosane:

It is contemplated that more that one alkyl halide can be used in thesame reaction. It is also understood that more or less than one molarequivalent of the halide can be added and that reaction product (ormixture of reaction products) can be controlled by stoichiometry ofstarting materials.

In a further aspect, a C₁-C₂₀ alkylsilyl (e.g., trimethylsilyl ort-butyldimethylsilyl) group can be used:

In a further aspect, a poly(ethylene glycol/butylene glycol) copolymer,dialkyl ether can be prepared:

It is understood that any one or more of the disclosed aspects,examples, or species can optionally be excluded from the invention.

3. Solvation

In one aspect, the disclosed solvents exhibit superior salvation ofsilicone polymers and/or prepolymers. Solvation can be determined bytests in which a sample of the solvent is used to dissolve a number ofdifferent polymers or prepolymers. By observing whether the polymer orprepolymer is dissolved, swelled, or unchanged, it is possible toascertain whether and to what extent a prepolymer is soluble in a givensolvent system. See Hansen Solubility Parameters; A User's Handbook,Charles M. Hansen, pp. 43-53, CRC Press 2000. For example, a known massof prepolymer can be exposed to an excess amount of a given solventsystem for a period of time (e.g., 10 minutes). The mixture can beoptionally sonicated and/or exposed to elevated temperature. Afterwards,any undissolved prepolymer can be removed by decantation or byfiltration, and the proportion dissolved within the solvent system canbe calculated.

Solvation can be determined by using a protocol of the following example(note that wt % is an example for 60 wt % solid solution): (1) Irgacure819 (a photo-initiator, 0.42 wt %) and a prepolymer (55.38 wt %) areadded into a solvent to form a mixture. (2) The mixture is mixed wellwith a touch mixer and by sonication. (3) The mixture is put in an ovenat 70° C. for about one hour. (4) The mixture removed from the oven andmixed with a spatula. (5) The mixture is put in the oven again foranother 40 minutes. (6) Repeat steps 4 and 5. (7) If the mixture isclear and phase separation is not observed when the mixture is taken outfrom the oven, it is considered “soluble.” If the mixture is hazy orphase separation is observed, it is considered “insoluble.”

4. Co-Solvents

It is also contemplated that the disclosed solvents can be used incombination with one or more co-solvents. In one aspect, the identityand amount of co-solvent is selected so as to not decrease thesolubility of a prepolymer or polymer in a disclosed solvent. Suitableco-solvents include water-soluble solvents such as ethylene glycol,propylene glycol, polyethylene glycol, polypropylene glycol, ethyleneglycol-propylene glycol copolymer, and mixtures thereof. Furthersuitable co-solvents include methanol, ethanol, tetrahydrofuran,N,N-dimethylformamide, acetone, and acetonitrile.

E. PREPOLYMERS

In one aspect, the invention relates to one or more siliconeprepolymers. More specifically, compounds are disclosed whereinundesirable shrinkage, expansion, and related problems possessed byconventional silicone monomers and related conventional polymerizationtechniques can be overcome by producing hydrogels from a crosslinkableprepolymer having a relatively low molecular weight and lowpolydispersity. Moreover, the disclosed prepolymers are prepared havingstructures that provide satisfactory solubilities in aqueous solutionsor hydrophilic solutions, such as PEG/PVP, as well as desirable oxygenpermeabilities.

1. Structure

In one aspect, a prepolymer can be a compound or collection of compoundscomprising at least one silicone-containing residue having a structurerepresented by the formula:

wherein R^(a) represents hydrogen or methyl, and wherein A represents asiloxanyl group; and at least one polymerizable residue having astructure represented by the formula:

wherein R^(p) represents hydrogen or methyl, and wherein P represents anorganic group comprising at least one polymerizable moiety; wherein theprepolymer has a silicon content of from about 10% to about 30% byweight, of the prepolymer; wherein at least one of the at least onesilicone-containing residue is a polar silicone-containing residuefurther comprising at least one polar moiety; and wherein the prepolymerhas a polar silicone-containing residue content of from about 30% toabout 90% by weight of the prepolymer.

a. Siloxanyl Groups

In one aspect, the disclosed prepolymers comprise one or more siloxanylgroups. Unless otherwise specifically described, a siloxanyl group canbe any siloxanyl group known to those of skill in the art.

In a further aspect, at least one A has a structure represented by theformula:

wherein L represents a C₁-C₂₀ alkyl residue or a C₁-C₂₀ aryl residue;and wherein D represents a siloxanyl group. In a still further aspect,at least one A has a structure represented by the formula:

wherein G represents a C₁-C₂₀ alkyl residue or a C₁-C₂₀ aryl residue,which alkyl residue or aryl residue further comprises at least onehydroxyl group; wherein L represents a C₁-C₂₀ alkyl residue or a C₁-C₂₀aryl residue; and wherein D represents a siloxanyl group.

In a further aspect, D has a structure represented by the formula:

wherein E¹ to E¹¹ independently represent hydrogen, an optionallysubstituted C₁-C₂₀ alkyl residue, or an optionally substituted C₆-C₂₀aryl residue; wherein h represents an integer of from 0 to 200; andwherein i, j, and k independently represent integers of from 0 to 20,with the proviso that h, i, j and k are not simultaneously zero.

In a further aspect, at least one A has a structure represented by theformula:

wherein n represents an integer of from 3 to 10; and wherein R₅represents a C₁-C₂₀ alkyl residue or a C₁-C₂₀ aryl residue.

It is understood that any one or more of the disclosed aspects,examples, or species can optionally be excluded from the invention.

b. Hydrophilic Residues

In one aspect, the disclosed prepolymers comprise one or morehydrophilic residues. Unless otherwise specifically described, ahydrophilic residue can be any hydrophilic residue known to those ofskill in the art. In certain aspects, hydrophilic residues can be absentfrom the disclosed prepolymers.

In a further aspect, a prepolymer can further comprise at least one atleast one hydrophilic residue having a structure represented by theformula:

wherein R^(b) represents hydrogen or methyl; and wherein B represents ahydrophilic group.

In a further aspect, a hydrophilic residue comprises one or moreresidues of N,N-dimethylacrylamide, 2-hydroxyethyl methacrylate,N-vinylpyrrolidone, N-vinylformamide, N-vinylacetamide, (meth)acrylicacid, N-vinyl-2-piperidone, N-vinyl-2-caprolactam,N-vinyl-3-methyl-2-caprolactam, N-vinyl-3-methyl-2-piperidone,N-vinyl-4-methyl-2-piperidone, N-vinyl-4-methyl-2-caprolactam,N-vinyl-3-ethyl-2-pyrrolidone, N-vinyl-4,5-dimethyl-2-pyrrolidone, orN-vinylimidazole.

It is understood that any one or more of the disclosed aspects,examples, or species can optionally be excluded from the invention.

c. Polar Moieties

In one aspect, the disclosed prepolymers comprise one or more polarmoieties. Unless otherwise specifically described, a polar moiety can beany polar moiety known to those of skill in the art. In a furtheraspect, a polar moiety can be hydroxyl, amide, carboxyl, amino,carbonate, carbamate, sulfonamide, sulfonic, phosphonic, methoxyethyl,methoxyethoxyethyl, hydroxyethyl, or hydroxyethoxyethyl.

It is understood that any one or more of the disclosed aspects,examples, or species can optionally be excluded from the invention.

d. Polymerizable Residues

In one aspect, the disclosed prepolymers comprise one or morepolymerizable residues or groups. Unless otherwise specificallydescribed, a polymerizable residue can be any polymerizable residueknown to those of skill in the art. In a further aspect, a polymerizableresidue comprises one or more ethylenically unsaturated moieties, forexample, a methacryloyloxy group, an acryloyloxy group, a methacrylamide group, an acryl amide group, a styryl group, a vinyl group, avinyl carbonate group, a vinyl carbamate group, an allyl carbonategroup, or an allyl carbamate group.

In a further aspect, a polymerizable residue is obtained by reacting aunit having a structure represented by the formula:

wherein R^(z) represents hydrogen or methyl; wherein Z represents anoptionally substituted C₁-C₂₀ alkyl residue or an optionally substitutedC₆-C₂₀ aryl residue, which alkyl or aryl further comprises at least oneof an hydroxyl group, a carboxyl group, an ester group, or a carboxylicanhydride group; with at least one compound having at least onepolymerizable residue.

In a further aspect, Z comprises one or more of:

a halogenocarbonyl group, a (meth)acryloyloxycarbonyl group, a carboxylgroup, a C₁-C₂₀ alkyloxycarbonyl group, a 2-aminoethoxycarbonyl group, a4-halogenocarbophenyl group, a 4-carboxyphenyl group, or a 4-(C₁-C₂₀alkyloxycarbonyl)phenyl group.

In one aspect, the compound having at least one polymerizable group is2-isocyanatoethyl(meth)acrylate, (meth)acryloyl isocyanate,

(meth)acrylic acid halide, (meth)acrylic anhydride, (meth)acrylic acid,methyl(meth)acrylate, ethyl(meth)acrylate, 2-hydroxyethyl(meth)acrylate,2-aminoethyl(meth)acrylate, 4-vinylbenzoic acid halide, 4-vinylbenzoicanhydride, or 4-vinylbenzoic acid ester.

In a further aspect, at least one polymerizable moiety has a structurerepresented by the formula:

wherein R represents hydrogen or methyl.

It is understood that any one or more of the disclosed aspects,examples, or species can optionally be excluded from the invention.

e. Terminal Groups

It is understood that the disclosed prepolymers can have terminal groupsresulting from the initiation and termination of the polymerizationreaction used to prepare the prepolymer. For example, a prepolymer canhave a terminal group resulting from the initiation reaction and havinga structure represented by a formula:

wherein A, B, and P represent a siloxanyl group, a hydrophilic group,and a polymerizable group, as described herein. In the above structures,the symbol IN represents a residue of an initiator, for example, an azoinitiator or a peroxide initiator.

A prepolymer can also have a terminal group resulting from thetermination reaction and having a structure represented by a formula:

wherein A, B, and P represent a siloxanyl group, a hydrophilic group,and a polymerizable group, as described herein. In the above structures,the symbol T represents a residue of a terminator, for example, ahydrogen atom extracted from water or other protic solvent.

It is also understood that the disclosed prepolymers can have analogousterminal groups resulting from analogous initiation and terminationreactions with comonomers.

It is understood that any one or more of the disclosed aspects,examples, or species can optionally be excluded from the invention.

2. Silicon Content

In one aspect, a disclosed prepolymer can have a silicon content of fromabout 10% to about 30% by weight. In a further aspect, a disclosedprepolymer can have a silicon content of from about 13% to about 20% byweight. For example, the silicon content can be from about 15% to about20%, from about 13% to about 18%, from about 15% to about 18%, about13%, about 15%, about 18%, or about 20%. It is also understood that adisclosed silicon content can represent the average silicon content fora collection of silicone prepolymers.

In a further aspect, the total of the polar silicone units can be fromabout 50% 10 to about 80% by weight, based on solid content of theprepolymer. For example, the total of the polar silicone units can befrom about 55% to about 80%, from about 60% to about 80%, from about 50%to about 75%, from about 50% to about 70%, from about 60% to about 70%,or from about 55% to about 75%. It is also understood that a disclosedtotal of the polar silicone units can represent the average total for acollection of silicone prepolymers.

In a further aspect, the content of the polymerizable unit can be fromabout 0.1 to about 15 mol %, based on the prepolymer. For example, thecontent of the polymerizable unit can be from about 0.25 mol % to about15 mol %, from about 0.5 mol % to about 15 mol %, from about 1 mol % toabout 15 mol %, from about 0.1 mol % to about 12 mol %, from about 0.1mol % to about 10 mol %, from about 0.1 mol % to about 5 mol %, or fromabout 0.1 mol % to about 10 mol %. It is also understood that adisclosed content of the polymerizable unit can represent the averagecontent of the polymerizable unit for a collection of siliconeprepolymers.

It is understood that any one or more of the disclosed aspects,examples, or species can optionally be excluded from the invention.

3. Solubility

In one aspect, the disclosed prepolymers exhibit superior solubility inaqueous solutions or hydrophilic solutions, such as e.g. PEG/PVP.Solubility can be determined by solubility tests in which a sample ofthe prepolymer is stored in a number of different solvents. By observingwhether the polymer is dissolved, swelled, or unchanged, it is possibleto ascertain whether and to what extent a prepolymer is soluble in agiven solvent system. See Hansen Solubility Parameters; A User'sHandbook, Charles M. Hansen, pp. 43-53, CRC Press 2000. For example, aknown mass of prepolymer can be exposed to an excess amount of a givensolvent system for a period of time (e.g., 10 minutes). The mixture canbe optionally sonicated and/or exposed to elevated temperature.Afterwards, any undissolved prepolymer can be removed by decantation orby filtration, and the proportion dissolved within the solvent systemcan be calculated.

Solubility can be determined by using a protocol of the followingexample (note that wt % is an example for 60 wt % solid solution): (1)Irgacure 819 (a photo-initiator, 0.42 wt %) and a prepolymer (55.38 wt%) are added into PEG (40 wt %)/PVP (4.2 wt %) solution. (2) The mixtureis mixed well with a touch mixer and by sonication. (3) The mixture isput in an oven at 70° C. for about one hour. (4) The mixture removedfrom the oven and mixed with a spatula. (5) The mixture is put in theoven again for another 40 minutes. (6) Repeat steps 4 and 5. (7) If themixture is clear and phase separation is not observed when the mixtureis taken out from the oven, it is considered “soluble.” If the mixtureis hazy or phase separation is observed, it is considered “insoluble.”

In one aspect, a prepolymer can have a solubility of not less than about50% by weight, based on solid content of the prepolymer, in awater-soluble solvent. For example, the solubility can be at least about55%, at least about 60%, at least about 65%, at least about 70%, atleast about 75%, at least about 80%, at least about 85%, or at leastabout 90%. It is understood that, in one aspect, the solubility can beaffected by the average molecular weight of the prepolymer composition.That is, prepolymer having a certain molecular weight or less can besoluble, while prepolymer having a certain molecular weight or more canbe less soluble.

In one aspect, prepolymer can have a solubility of not less than about50% by weight (e.g., at least about 55%, at least about 60%, at leastabout 65%, at least about 70%, at least about 75%, at least about 80%,at least about 85%, or at least about 90%), based on solid content ofthe prepolymer, in a water-soluble solvent comprising from about 1% toabout 20% (e.g., from about 1% to about 5%, from about 5% to about 10%,from about 2% to about 8%, about 2%, about 3%, about 4%, about 5%, about6%, about 7%, about 8%, or about 9%) by weight of polyvinylpyrrolidone.

Solvent systems suitable for use with the disclosed prepolymers includethe disclosed solvents. Further suitable co-solvents includewater-soluble solvents such as ethylene glycol, propylene glycol,polyethylene glycol, polypropylene glycol, ethylene glycol-propyleneglycol copolymer, and mixtures thereof.

4. Molecular Weight

In one aspect, the disclosed prepolymers can have an average molecularweight of from about 10 kD to about 1000 kD, for example from about 10kD to about 500 kD, from about 10 kD to about 300 kD, or from about 10kD to about 200 kD. In one aspect, the polydispersity (M_(w)/M_(n)) ofthe disclosed prepolymers can be from about 1.00 to about 10.00. Forexample, the polydispersity can be from about 1.00 to about 9.00, fromabout 1.00 to about 8.00, from about 1.00 to about 7.00, from about 1.00to about 6.00, or from about 1.00 to about 5.00. In a further aspect,the polydispersity can be less than about 8, for example, less thanabout 7.5, less than about 7, less than about 6.5, less than about 6,less than about 5.5, less than about 5, less than about 4.5, or lessthan about 4.

5. Comonomers

It is also contemplated that the disclosed prepolymers can furthercomprise residues from further comonomers, so long as the prepolymerretains a silicon content of from about 10% to about 30% by weight, ofthe prepolymer and a polar silicone-containing residue content of fromabout 30% to about 90% by weight of the prepolymer. Preferred examplesof such comonomers include alkyl(meth)acrylates such as (meth)acrylicacid, itaconic acid, crotonic acid, cinnamic acid, vinylbenzoic acid,methyl(meth)acrylate and ethyl (meth)acrylate; polyfunctional(meth)acrylates such as polyalkylene glycol mono(meth)acrylate,polyalkylene glycol monoalkyl ether (meth)acrylate, polyalkylene glycolbis(meth)acrylate, trimethylolpropane tris(meth)acrylate,pentaerythritol tetrakis(meth)acrylate, polydimethyl siloxane having(meth)acryloxypropyl group at both ends, polydimethyl siloxane having(meth)acryloxypropyl group at one end and polydimethyl siloxane having aplurality of (meth)acryloyl groups in side chains; halogenated alkyl(meth)acrylates such as trifluoroethyl(meth)acrylate andhexafluoroisopropyl(meth)acrylate; hydroxyalkyl(meth)acrylates havinghydroxyl group such as 2-hydroxyethyl(meth)acrylate,2-hydroxypropyl(meth)acrylate and 2,3-dihydroxypropyl(meth)acrylate;(meth)acrylamides such as N,N-dimethylacrylamide, N,N-diethylacrylamide,N,N-di-n-propylacrylamide, N,N-diisopropylacrylamide,N,N-di-n-butylacrylamide, N-acryloylmorpholine, N-acryloylpiperidine,N-acryloylpyrrolidine and N-methyl(meth)acrylamide; N-vinyl-N-methylacetamide, N-vinyl-N-ethyl acetamide, N-vinyl-N-ethyl formamide, N-vinylformamide, aromatic vinyl monomers such as styrene, α-methylstyrene andvinylpyridine; maleimides; heterocyclic vinyl monomers such asN-vinylpyrrolidone; 3-[tris(trimethylsiloxy)silyl]propyl (meth)acrylate,3-[bis(trimethylsiloxy)methylsilyl]propyl(meth)acrylate,3-[(trimethylsiloxy)dimethylsilyl]propyl(meth)acrylate,3-[tris(trimethylsiloxy)silyl]propyl (meth)acrylamide,3-[bis(trimethylsiloxy)methylsilyl]propyl(meth)acrylamide,3-[(trimethylsiloxy)dimethylsilyl]propyl(meth)acrylamide,[tris(trimethylsiloxy)silyl]methyl (meth)acrylate,[bis(trimethylsiloxy)methylsilyl]methyl(meth)acrylate,[(trimethylsiloxy)dimethylsilyl]methyl(meth)acrylate,[tris(trimethylsiloxy)silyl]methyl (meth)acrylamide,[bis(trimethylsiloxy)methylsilyl]methyl(meth)acrylamide,[(trimethylsiloxy)dimethylsilyl]methyl(meth)acrylamide,[tris(trimethylsiloxy)silyl]styrene,[bis(trimethylsiloxy)methylsilyl]styrene,[(trimethylsiloxy)dimethylsilyl]styrene, polydimethyl siloxane having(meth)acryloxypropyl group at one end, and compounds represented byFormula (C1-1) to (C6-1) and (C1-2) to (C6-2) below.

Other silicone containing components suitable for use in this inventioninclude those described is WO 96/31792 such as macromers containingpolysiloxane, polyalkylene ether, diisocyanate, polyfluorinatedhydrocarbon, polyfluorinated ether and polysaccharide groups. U.S. Pat.Nos. 5,321,108; 5,387,662; and 5,539,016 describe polysiloxanes with apolar fluorinated graft or side group having a hydrogen atom attached toa terminal difluoro-substituted carbon atom. US 2002/0016383 describehydrophilic siloxanyl methacrylates containing ether and siloxanyllinkages and crosslinkable monomers containing polyether andpolysiloxanyl groups.

In one embodiment comonomers include (meth)acrylic acid, 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, N,N-dimethylacrylamide,N-vinyl pyrrolidone, N-vinyl-N-methyl acetamide, N-vinyl-N-ethylacetamide, 3-[tris(trimethylsiloxy)silyl]propyl(meth)acrylate,3-[bis(trimethylsiloxy)methylsilyl]propyl (meth)acrylate, the compoundsC1-1, C2-1, C3-1, C4-1, C5-1, C6-1, C1-2, C2-2, C3-2, C4-2, C5-2, C6-2,polysiloxane macromers, hydrophilic siloxyanly methacrylates containingether and siloxanyl linkages and combinations thereof and the like.

Further preferred examples of such monomers include 2-propenoic acid,2-methyl-2-hydroxy-3-[3-[1,3,3,3-tetramethyl-1-[(trimethylsilyl)oxy]disiloxanyl]propoxy]propylester (SiGMA); monomethacryloxypropyl-terminated mono-n-butyl terminatedpolydimethylsiloxane (mPDMS; MW 800-1000 (Me));bis-3-acryloxy-2-hydroxypropyloxypropyl polydimethylsiloxane (acPDMS)(MW 1000 and 2000, acrylated polydimethylsiloxane from Gelest andDegussa, respectively); methacryloxypropyl-terminatedpolydimethylsiloxane (MW 550-700) from Gelest (maPDMS); andmono-(3-methacryloxy-2-hydroxypropyloxy)propyl terminated, mono-butylterminated polydimethylsiloxane (mPDMS-OH).

F. METHODS OF MAKING PREPOLYMERS

In one aspect, the invention relates to a method of preparing aprepolymer. It is understood that the compounds, structures, andmoieties disclosed in connection with the prepolymers can also be usedin connection with the disclosed methods.

In one aspect, the disclosed prepolymers can be prepared by a methodcomprising the steps of providing a mixture comprising at least onemonomer having a siloxanyl group, wherein at least one of the at leastone monomer having a siloxanyl group is a polar silicone-containingmonomer further comprising at least one polar moiety; at least onemonomer having a polymerizable group; optionally, at least one comonomer(e.g., HEMA); and, optionally, at least one monomer having a hydrophilicgroup; reacting the monomers by heating the mixture at a reactiontemperature (e.g., from about 50° C. to about 60° C.) for a reactiontime (e.g., from about 2 hours to about 6 hours), and/or exposing themixture to a radical initiator (e.g.,2,2′-azobis(2,4-dimethylvaleronitrile)), thereby polymerizing themonomers to provide an unfunctionalized intermediate polymer; combiningthe unfunctionalized intermediate polymer with a reactive compound(e.g., 2-isocyanate ethyl methacrylate) bearing an ethylenicallyunsaturated moiety (e.g., an acryloyl moiety); optionally, apolymerization inhibitor (e.g., 2,6-di-t-butyl-4-methylphenol); and,optionally, a catalyst (e.g., dibutyltindilauric acid); allowing thereactive compound to functionalize the unfunctionalized intermediatepolymer, thereby providing a prepolymer, wherein the relative proportionof monomers in the mixture are selected to provide a prepolymer with asilicon content of from about 10% to about 30% by weight, of theprepolymer and a polar silicone-containing residue content of from about30% to about 90% by weight of the prepolymer. In a further aspect, theat least one monomer having a siloxanyl group, and the at least onemonomer having a polymerizable group can be the same monomer.

In a further aspect, the disclosed prepolymers can be prepared by amethod comprising the steps of providing a mixture comprising at leastone monomer having a siloxanyl group, wherein at least one of the atleast one monomer having a siloxanyl group is a polarsilicone-containing monomer further comprising at least one polarmoiety; at least one monomer having a polymerizable group (e.g., vinylmethacrylate, which has two polymerizable groups having differentpolymerizabilities); optionally, at least one comonomer (e.g., HEMA);and, optionally, at least one monomer having a hydrophilic group;reacting the monomers by heating the mixture at a reaction temperature(e.g., from about 50° C. to about 60° C.) for a reaction time (e.g.,from about 2 hours to about 6 hours), and/or exposing the mixture to aradical initiator (e.g., 2,2′-azobis(2,4-dimethylvaleronitrile)),thereby providing a prepolymer, wherein the relative proportion ofmonomers in the mixture are selected to provide a prepolymer with asilicon content of from about 10% to about 30% by weight, of theprepolymer and a polar silicone-containing residue content of from about30% to about 90% by weight of the prepolymer.

It is understood that solvent can be removed (e.g., by evaporation)after production of the intermediate polymer and/or after production ofthe prepolymer. It is also understood that either or both of theintermediate polymer and the prepolymer can be purified by, for example,washing, filtration, and/or distillation. Purification can beaccomplished by, for example, conventional distillation or by reducedpressure distillation (e.g., thin film distillation), optionally in thepresence of a polymerization inhibitor, for example, one or more of analkylhydroquinone or a hydroxynaphthalene. That is, in a further aspect,the disclosed prepolymers can be purified by removing lower molecularweight impurities by distillation, for example, reduced pressuredistillation. Such a purification method can comprise the steps of: (1)providing a prepolymer mixture or a crude prepolymer, and (2) reducedpressure distillation of lower molecular weight impurities from theprepolymer mixture or the crude prepolymer in the presence of at leastone polymerization inhibitor comprising an alkylhydroquinone or ahydroxynaphthalene. In a further aspect, the method further comprisesthe step of collecting the distilled siloxanyl monomer. The monomer canbe collected, for example, in a receiving vessel. In one aspect, thepolymerization inhibitor can comprise one or more of analkylhydroquinone or a hydroxynaphthalene.

Typically, after the intermediate polymer or prepolymer has been formed,substantially all unreacted reactants and byproducts are removed. By“substantially all,” it is meant that less than about 0.1 weight %remains after purification. This can be done by conventional means, suchas ultrafiltration. However, it is possible to purify the intermediatepolymer or prepolymer by swelling with water and rinsing with water toremove substantially all of the undesired constituents includingmonomeric, oligomeric, or polymeric starting compounds and catalystsused in the preparation and byproducts formed during the preparation ofthe intermediate polymer or prepolymer. The washing can be conductedwith deionized water and conditions can be selected to provide a largesurface to volume ratio of the intermediate polymer or prepolymerparticles. This can be done by freeze drying the intermediate polymer orprepolymer, making a thin film from the intermediate polymer orprepolymer, extruding the intermediate polymer or prepolymer into rods,nebulizing the intermediate polymer or prepolymer solution into thedeionized water, and other like methods, which are known to thoseskilled in the art.

In a further aspect, a polymerizable residue can be obtained by reactinga unit having a structure represented by the formula:

wherein R^(z) represents hydrogen or methyl; wherein Z represents anoptionally substituted C₁-C₂₀ alkyl residue or an optionally substitutedC₆-C₂₀ aryl residue, which alkyl or aryl further comprises at least oneof an hydroxyl group, a carboxyl group, an ester group, or a carboxylicanhydride group; with at least one compound having at least onepolymerizable residue.

G. POLYMERS, COMPOSITIONS, AND APPLICATIONS THEREOF

In one aspect, the prepolymers can be used to prepare further polymersby, for example, a thermally-initiated or photo-initiated polymerizationor crosslinking reaction. Accordingly, in a further aspect, theinvention relates to a polymer obtained by polymerizing or cross-linkingone or more of the disclosed prepolymers. That is, in one aspect, theinvention relates to methods for producing a polymer comprising the stepof polymerizing prepolymer from the disclosed compositions, therebyproviding the polymer.

Additionally, the disclosed polymers can be used to prepare medicaldevices, such as ophthalmic lenses, for example contact lenses,intraocular implants, and artificial cornea; stents, implants, andcatheters; and other optical devices. Accordingly, in a further aspect,the invention relates to an ophthalmic lens, contact lens, intraocularimplant, artificial cornea, stent, implant, catheter; or other opticaldevice obtained by polymerizing or cross-linking one or more of thedisclosed prepolymers.

The present invention provides a material from which molded plasticshaving a desirable oxygen permeability, hydrophilicity and resistance tobreakage may be produced by polymerizing the material. The moldedplastics are useful as drug adsorbents used for drug delivery, andophthalmic lenses such as contact lenses, intraocular lenses, artificialcornea and spectacle lenses. Among these, they are particularly suitedfor contact lenses.

In one aspect, the compositions can provide materials for producingmolded plastics, which material is excellent in compatibility withhydrophilic monomers such as 2-hydroxyethyl methacrylate, which iscapable of yielding molded plastics, by polymerizing the material toform articles having a desirable combination of properties, includingoxygen permeability, hydrophilicity, and a low modulus of elasticity, aswell as excellent optical quality.

By the present invention, a material for producing molded plastics maybe provided, which material is excellent in compatibility withhydrophilic monomers such as, but not limited to 2-hydroxyethylmethacrylate, N-vinyl pyrrolidone, N,N-dimethylacrylamide,N-vinyl-N-methyl acetamide combinations thereof and the like which iscapable of yielding molded plastics, by polymerizing the material,having a desirable combination of properties, including, oxygenpermeability, hydrophilicity and a low modulus of elasticity, as well asexcellent optical quality.

1. Molded Articles

In one aspect, the compounds and compositions of the invention can beused to provide a molded article comprising at least one of thecompositions of the invention. In a further aspect, the compounds andcompositions of the invention can be used to provide an ophthalmic lenscomprising at least one of the compositions of the invention. In a yetfurther aspect, the compounds and compositions of the invention can beused to provide a contact lens comprising at least one of thecompositions of the invention.

Molded articles, e.g. contact lenses, can be prepared by furtherpolymerizing or crosslinking the disclosed prepolymers, either alone orwith one or more other of the comonomers or materials described herein.For preparing the molded articles, especially ophthalmic lenses,additional materials may also be included in the polymerization mixture.For example, a crosslinker having two or more polymerizablecarbon-carbon unsaturated bonds in the molecule can be included toobtain good mechanical properties and good resistance to antisepticsolutions and washing solutions. The percentage of the crosslinker,based on the total monomers to be copolymerized, is preferably not lessthan about 0.01% by weight, more between about 0.05% and about 15% byweight, still more preferably between about 0.1% and about 5% by weight.In certain aspects, because the disclosed prepolymers comprisepolymerizable moieties, additional crosslinker may be omitted.

From the viewpoint of simultaneously attaining a desired oxygenpermeability and hydrophilicity, the percentage of the material forproducing molded plastics according to the present invention in theprepared molded plastics is, in cases where other siloxanyl-groupcontaining polymerizable material is not copolymerized, preferably fromabout 30% by weight to about 100% by weight, more preferably from about50% by weight to about 99% by weight, still more preferably from about60% by weight to about 95% by weight. In cases where one or more othersiloxanyl group-containing polymerizable materials are copolymerized,the percentage of the total of the material according to the presentinvention and the other siloxanyl group-containing polymerizablematerial(s) in the prepared molded plastics is preferably from about 30%by weight to about 100% by weight, more preferably from about 50% byweight to about 99% by weight, still more preferably from about 60% byweight to about 95% by weight.

2. Additives

The molded plastics may contain additional components, including, butnot limited to UV absorbers, colorants, coloring agents, wetting agents,slip agents, pharmaceutical and nutraceutical components,compatibilizing components, antimicrobial compounds, release agents,combinations thereof and the like. Any of the foregoing may beincorporated in non-reactive, polymerizable, and/or copolymerized form.

3. Polymerization Procedures

In the polymerization or crosslinking for preparing molded articles, itis preferred to add a thermal polymerization initiator orphotopolymerization initiator typified by peroxides and azo compoundsfor easily attaining polymerization. In cases where thermalpolymerization is carried out, one having the optimum decompositioncharacteristics at the satisfactory reaction temperature is selected. Ingeneral, azo initiators and peroxide initiators having a 10 hourhalf-life temperature of from about 40° C. to about 120° C. arepreferred. Examples of the photoinitiator include carbonyl compounds,peroxides, azo compounds, sulfur compounds, halogenated compounds andmetal salts. These polymerization initiators can be used individually orin combination. The amount of the polymerization initiator(s) can be upto about 1% by weight based on the polymerization mixture.

In (co)polymerizing the material for producing molded plastics accordingto the present invention, a polymerization solvent can be used. As thesolvent, various organic and inorganic solvents can be employed.Examples of the solvents include water; alcoholic solvents such asmethyl alcohol, ethyl alcohol, normal propyl alcohol, isopropyl alcohol,normal butyl alcohol, isobutyl alcohol, tert-butyl alcohol, ethyleneglycol, diethylene glycol, triethylene glycol, tetraethylene glycol andpolyethylene glycol; glycol ether solvents such as methyl cellosolve,ethyl cellosolve, isopropyl cellosolve, butyl cellosolve, propyleneglycol monomethyl ether, diethylene glycol monomethyl ether, triethyleneglycol monomethyl ether, polyethylene glycol monomethyl ether, ethyleneglycol dimethyl ether, diethylene glycol dimethyl ether, triethyleneglycol dimethyl ether and polyethylene glycol dimethyl ether; estersolvents such as ethyl acetate, butyl acetate, amyl acetate, ethyllactate and methyl benzoate; aliphatic hydrocarbon solvents such asnormal hexane, normal heptane and normal octane; alicyclic hydrocarbonsolvents such as cyclohexane and ethylcyclohexane; ketone solvents suchas acetone, methyl ethyl ketone and methyl isobutyl ketone; aromatichydrocarbon solvents such as benzene, toluene and xylene; and petroleumsolvents. These solvents can be used individually or two or more ofthese solvents can be used in combination.

4. Molding Procedures

As the method of polymerization of the material for producing moldedarticles according to the present invention, and as the method ofmolding the plastics, known methods can be employed. For example, amethod in which the material is once polymerized and molded into theshape of round bar or plate and the resulting round bar or plate is thenprocessed into the satisfactory shape by cutting or the like, moldpolymerization method and spin cast polymerization method can beemployed.

As an example, a process for producing an ophthalmic lens from thedisclosed prepolymers will now be described. First, a gap having aprescribed shape, between two mold parts, is filled with a prepolymercomposition and photopolymerization or thermal polymerization is carriedout to shape the composition into the shape of the gap between themolds. The molds are made of a resin, glass, ceramics, metal, or thelike. In case of photopolymerization, an optically transparent materialis used, and a resin or glass is usually used. In case of producing anophthalmic lens, a gap is formed between two mold parts facing eachother, and the gap is filled with the material composition. Depending onthe shape of the gap and on the properties of the material composition,a gasket may be used in order to give the ophthalmic lens a prescribedthickness and to prevent leakage of the material composition filled inthe gap. The molds containing the gap filled with the materialcomposition are then irradiated with an actinic radiation such asultraviolet light, visible light or a combination thereof, or placed inan oven or bath to heat the material composition, thereby carrying outpolymerization. The two polymerization methods may be employed incombination, that is, thermal polymerization may be carried out afterphotopolymerization, or photopolymerization may be carried out afterthermal polymerization. In photopolymerization embodiment, a lightcontaining ultraviolet light, such as the light from a mercury lamp orUV lamp (e.g., FL15BL, TOSHIBA corporation) is radiated for a short time(usually not longer than 1 hour). In cases where thermal polymerizationis carried out, it is preferred to employ conditions in which thecomposition is slowly heated from room temperature to a temperature fromabout 60° C. to about 200° C. over a period of several hours to severaltens hours, in view of the optical uniformity, high quality, and highreproducibility of the ophthalmic lens.

The molded articles produced from the disclosed prepolymer can have adynamic contact angle (during forward movement, immersion rate: about0.1 mm/sec) of, for example, not more than about 130°, more preferablynot more than about 120°, still more preferably not more than about100°. The water content thereof is preferably from about 3% to about50%, more preferably from about 5% to about 50%, still more preferablyfrom about 7% to about 50%.

Generally, for contact lenses, higher oxygen permeabilities aredesirable. In one aspect, the oxygen permeability coefficient [×10⁻¹¹(cm²/sec)mLO₂/(mL·hPa)] is preferably not less than about 50, morepreferably not less than about 60, still more preferably not less thanabout 65. In certain aspects, the oxygen permeability coefficient can beat least about 90, at least about 95, at least about 100, at least about105, or at least about 110. The tensile modulus of elasticity ispreferably from about 0.01 to about 30 MPa, more preferably from about0.1 to about 7 MPa. The tensile elongation is preferably not less thanabout 50%, more preferably not less than about 100%. Since a highertensile elongation gives higher resistance to breakage, it is preferredthat the molded plastics have a high tensile elongation. Theseproperties may be measured using the test methods disclosed inWO03/022321.

H. EXPERIMENTAL

The following examples are put forth so as to provide those of ordinaryskill in the art with a complete disclosure and description of how thecompounds, compositions, articles, devices and/or methods claimed hereinare made and evaluated, and are intended to be purely exemplary of theinvention and are not intended to limit the scope of what the inventorsregard as their invention. Efforts have been made to ensure accuracywith respect to numbers (e.g., amounts, temperature, etc.), but someerrors and deviations should be accounted for. Unless indicatedotherwise, parts are parts by weight, temperature is in ° C. or is atambient temperature, and pressure is at or near atmospheric.

1. Analytical Methods

Molecular weight: size exclusion chromatography (SEC) equipment iscomposed of a column oven at 40° C., a PE LC-410 pump with PE Nelson900A/D and a series 200 autosampler. The detector can be a RI MerckL7490. The column combination can consist of two TSK-Gel columns fromTosoHaas (G4000PW+G2500PW) and a guardcolumn. The eluent can be madewith methanol-water (75/25 wt/wt) and adjusted to 50 mM sodium chloride(NaCl). The flow rate can be 0.5 mL/minute. The injection volume is 150μL and the run time can be 60 minutes. A calibration curve can beobtained with third order regression using PEG and PEO of Peak molecularweights ranging from 960000 to 194 as standard references. These polymerstandards can be purchased from Polymer Laboratories Inc, Amherst Mass.(Calibration kits PEG-10 part No 2070-0100; PEO-10 part No 2080-0101).Added standard reference PEG of Peak molecular weight of 194 gives aflow signal at a well-defined position, which can be used as an internalstandard or fixation point. Added NaCl can play the same role and givesa second fixation point. Peak integrations can be made manually.Integration start and end points can be manually determined fromsignificant difference on global baseline. The injection solutions canbe prepared with methanol-water 75/25 wt/wt adjusted to 60 mM NaCl togive a polymer concentration of 2 mg/mL. Tetraethylene glycol can beadded to the sample in a concentration of 1 mg/ml in order to give apeak flow reference. The solutions are filtered on 0.5 μm disposablefilters before the injection is performed. Polydispersity, P_(d), of apolymer sample can be defined as P_(d)=M_(w)/M_(n). The peak molecularweight, M_(p), is the molecular weight of the highest peak in themolecular weight distribution curve.

Oxygen permeability: A sample's oxygen permeability was determined byusing a Seikaken-shiki film oxygen permeability meter manufactured byRIKA SEIKI KOGYO CO., LTD. The oxygen permeability coefficient of asample in the form of a film was measured in water at 35° C.(temperature controller not shown in Figure). Stirring was performed ata rate of 800 rpm with a 3 mm octagon-type MAGMIX magnetic stirrer(Mitamura Riken Kogyo Inc.). Four film samples with different thicknesswere prepared (0.1 mm, 0.2 mm, 0.3 mm, and 0.4 mm; diameter 16 mm). Thefour samples with different thickness were measured to determine Pm ofevery example (see FIG. 1); the graduation of the dial upright gaugeused was 0.001 mm; with an accuracy of about +/−0.003 mm. One of thesamples was set on an electrode. 0.5 N KCl (aqueous) was poured into theelectrode as an electrolytic solution (see FIGS. 2-4). The electrode wasset in distilled water (pH=7, volume=800 ml). At first, the currentunder nitrogen bubbling (flow rate=100 mL/min.; electric current, i, ismeasured after it is in equilibrium) was measured in order to adjustzero. Then the current under oxygen bubbling was measured. R wascalculated by the following formula: R=(Ps×N×F×A)/i [cm² sec mmHg/mL(STP)] (wherein Ps=760 mmHg (atmospheric pressure), N=4 (the number ofelectrons which involves a reaction at the electrode), F=96500coulomb/mol (Faraday constant), A=area of the electrode (cm²),i=measured current (uA)). R involves constant (not proportional) part,so plural measurement and plotting are necessary to determine Pm (seeFIG. 1). R versus the thickness of the samples was plotted. The inverseof the slope is the oxygen permeability coefficient (Pm).

In oxygen permeability testing, edge correction is typically consideredwhen the area of a material through which oxygen passes differs from onesurface of the sample to the other surface. In the present measurementmethod, the area of the hole of the ring which is set next to a filmsample (see FIG. 3, upper left portion) is the same as the area ofplatinum electrode, so edge correction is unnecessary.

Moisture Content: a sample in the form of a film sizing about 10 mm×10mm×0.2 mm was used. The sample was dried in a vacuum dryer at 40° C. for16 hours, and the weight (Wd) of the sample was measured. Thereafter,the resulting sample was immersed in pure water at 40° C. in athermostat bath overnight or more, and the moisture on the surface waswiped with Kimwipe, followed by measurement of the weight (Ww). Themoisture content was calculated according to the following equation:Moisture Content(%)=100×(Ww−Wd)/Ww

Tensile Test: a sample in the form of a film sizing about 19.5 mm×15mm×0.2 mm was used. The tensile modulus of elasticity was measured usingTensilon type RTM-100 manufactured by ORIENTEC. The speed of pulling was100 mm/min and the distance between grips was 5 mm.

2. Synthesis of Silicone Prepolymer A1

To a 300 mL three-necked flask equipped with a thermometer, three waystopcock, and mechanical stirrer, 33.44 g of a silicone monomer (SiMAA)represented by the following Formula (h):

36.00 g of a silicone monomer represented by the following Formula (1):

13.32 g of N,N-dimethylacrylamide (DMA), 6.12 g of 2-hydroxyethylmethacrylate (HEMA), 0.10 g of2,2′-azobis(2,4-dimethylvaleronitrile)(ADVN), 2.04 g of2-(2′-hydroxy-5′-methacryloxyethylphenyl)-2H-benzotriazole (UVabsorber), 0.0204 g of a dye represented by the following Formula (r):

1.00 g of 1-dodecylmercaptan (DSH), and 93.00 g of t-amyl alcohol (TAA)were added, and the atmosphere was replaced with argon. The mixture wasstirred under argon atmosphere at 50° C. for 0.5 hours and then at 60°C. for 4.5 hours, thereby polymerizing the monomers. After completion ofthe reaction, the solvent was evaporated with an evaporator. Theobtained solids were dissolved in 150 mL of methanol under heat, and theresulting solution was added to 300 mL of 40% (v/v) aqueous methanolsolution under stirring. The resulting mixture was left to stand, andthe supernatant was removed. The obtained precipitate was washed oncewith 300 mL of 65% (v/v) aqueous methanol solution and once with 300 mLof 75% (v/v) aqueous methanol solution. The obtained solids were driedunder vacuum at 40° C. for 18 hours and then pulverized after addingliquid nitrogen, followed by drying at 40° C. for 3 hours to obtain anunfunctionalized polymer.

To a 300 mL four-necked flask, 65 g of the obtained unfunctionalizedpolymer, 69 mg of 2,6-di-t-butyl-4-methylphenol (BHT), and 220 g of1,4-dioxane were added, and a mechanical stirrer, a connecting tubuleconnected to a nitrogen line, and a Claisen tube were mounted, and aLiebig condenser, siphon and eggplant type flask were connected to thetip of the Claisen tube. The temperature was raised to 110° C. whilestirring the mixture under nitrogen gas flow, and the temperature of110° C. was kept until about 110 g of 1,4-dioxane was evaporated,thereby eliminating moisture from the reaction system. After cooling themixture to 60° C., 30 μL of dibutyltindilauric acid (DBTDL) and 1.27 gof 2-isocyanate ethyl methacrylate (MOI) were added under nitrogen gasflow, and the resulting mixture was allowed to react at 60° C. for 3hours. After completion of the reaction, 50 mL of methanol was added,and the mixture was stirred for 15 minutes. The reaction solution wasconcentrated in an evaporator at 50° C., and 100 mL of methanol wasadded to the obtained concentrate to form a uniform solution. Theresulting solution was added to 300 mL of 70% (v/v) aqueous methanolsolution under stirring, and the mixture was left to stand, followed byremoval of the supernatant. The precipitate was further washed twicewith 300 mL of 85% (v/v) aqueous methanol solution. The obtained solidswere dried under vacuum at 40° C. for 18 hours, and then pulverizedafter adding liquid nitrogen, followed by drying at 40° C. for 3 hoursto obtain the desired silicone polymer.

3. Example A1

To 3.20 g of a solution containing 0.30 g of polyvinylpyrrolidone K90and 0.03 g of Irgacure 819 (CIBA specialty chemicals) dissolved in 2.87g of mono n-butyl poly(ethylene glycol-propylene glycol) randomcopolymer (average molecular weight: 200), 3.97 g of the siliconeprepolymer A1 was added, and the materials were mixed under heat at 70°C., followed by reducing the pressure to carry out degassing. Thesolubility was visually observed, and the results are shown in Table 2.

The obtained silicone prepolymer solution was deoxygenated under argonatmosphere and poured onto a glass plate with thin film (0.8 umthickness) in its peripheral area, under nitrogen (oxygen<0.5%), in aglove box at 55° C. The silicone prepolymer solution was covered withanother glass plate and irradiated with light (1.6 mW/cm², 10 minutes)with a fluorescent lamp (lamda max: 420 nm) to polymerize theprepolymer. After polymerization, the two glass plates were separatedand sonicated in borate buffer (pH 7.4 to 7.6) to demold the polymerfilm. The film was sterilized at 121° C. for 30 minutes, therebyobtaining a film sample. The transparencies of the film sample are shownin Table 2.

4. Comparative Examples A1 TO A6

The same operations as in Example A1 were repeated except that thesolvent of polymerization was changed as shown in Table 2. Thetransparency of the polymerization mixture and that of the film samplewere shown in Table 2.

TABLE 2 terminal molecular groups polymerization solvent weight (R¹¹,R¹³) mixture film Example A1 poly(EG + PG) random 200 (n-Bu, H) clearsolution transparent copolymer (50:50) mono(n-butyl) ether ComparativePEG 200 (H, H) clear solution not Example A1 transparent Comparative PPG200 (H, H) insoluble — Example A2 (prepolymer) Comparative PEG + PPG50:50 200, (H, H), insoluble — Example A3 mixture 200 (H, H)(prepolymer) Comparative PEG monomethyl ether 100 (Me, H) clear solutionnot Example A4 transparent Comparative PEG monomethyl ether 400 (Me, H)clear solution not Example A5 transparent Comparative PEG dimethyl ether500 (Me, Me) insoluble (PVP) — Example A6

5. Synthesis of Silicone Prepolymer B1

To a 300 mL three-necked flask equipped with a thermometer, three waystopcock, and mechanical stirrer, 100.32 g of a silicone monomer (SiMAA)represented by the following Formula (h):

108.00 g of a silicone monomer (OH-mPDMS) represented by the followingFormula (i):

46.44 g of N,N-dimethylacrylamide (DMA), 18.36 g of 2-hydroxyethylmethacrylate (HEMA), 0.279 g of2,2′-azobis(2,4-dimethylvaleronitrile)(ADVN), 6.12 g of2-(2′-hydroxy-5′-methacryloxyethylphenyl)-2H-benzotriazole (UVabsorber), 0.0612 g of a dye represented by the following Formula (r):

2.232 g of 1-dodecylmercaptan (DSH), and 279.24 g of t-amyl alcohol(TAA) were added, and the atmosphere was replaced with argon. Themixture was stirred under argon atmosphere at 50° C. for 0.5 hours andthen at 60° C. for 4.5 hours, thereby polymerizing the monomers. Aftercompletion of the reaction, the solvent was evaporated with anevaporator. The obtained solids were dissolved in 450 mL of methanolunder heat, and the resulting solution was added to 900 mL of 40% (v/v)aqueous methanol solution under stirring. The resulting mixture was leftto stand, and the supernatant was removed. The obtained precipitate waswashed once with 900 mL of 65% (v/v) aqueous methanol solution and oncewith 900 mL of 75% (v/v) aqueous methanol solution. The obtained solidswere dried under vacuum at 40° C. for 18 hours and then pulverized afteradding liquid nitrogen, followed by drying at 40° C. for 3 hours toobtain an unfunctionalized polymer.

To a 300 mL four-necked flask, 65 g of the obtained unfunctionalizedpolymer, 0.01 g of 2,6-di-t-butyl-4-methylphenol (BHT) and 220 g of1,4-dioxane were added, and a mechanical stirrer, a connecting tubuleconnected to a nitrogen line, and a Claisen tube were mounted, and aLiebig condenser, siphon and eggplant type flask were connected to thetip of the Claisen tube. The temperature was raised to 110° C. whilestirring the mixture under nitrogen gas flow, and the temperature of110° C. was kept until about 110 g of 1,4-dioxane was evaporated,thereby eliminating moisture from the reaction system. After cooling themixture to 60° C., 30 μL of dibutyltindilauric acid (DBTDL) and 1.733 gof 2-isocyanate ethyl methacrylate (MOI) were added under nitrogen gasflow, and the resulting mixture was allowed to react at 60° C. for 3hours. After completion of the reaction, 50 mL of methanol was added,and the mixture was stirred for 15 minutes. The reaction solution wasconcentrated in an evaporator at 50° C., and 100 mL of methanol wasadded to the obtained concentrate to form a uniform solution. Theresulting solution was added to 300 mL of 70% (v/v) aqueous methanolsolution under stirring, and the mixture was left to stand, followed byremoval of the supernatant. The precipitate was further washed twicewith 300 mL of 85% (v/v) aqueous methanol solution. The obtained solidswere dried under vacuum at 40° C. for 18 hours and then pulverized afteradding liquid nitrogen, followed by drying at 40° C. for 3 hours toobtain the desired silicone polymer.

6. Example B1

To 3.20 g of a solution containing 0.30 g of polyvinylpyrrolidone K90and 0.03 g of Irgacure 819 (CIBA specialty chemicals) dissolved in 2.87g of ethylene glycol mono n-butyl ether, 3.97 g of the siliconeprepolymer B1 was added, and the materials were mixed under heat at 70°C., followed by reducing the pressure to carry out degassing. Thesolubility was visually observed, and the results are shown in Table 3.

The obtained silicone prepolymer solution was deoxygenated under argonatmosphere and poured onto a glass plate with thin film (0.8 umthickness) in its peripheral area, under nitrogen (oxygen<0.5%), in aglove box at 55° C. The silicone prepolymer solution was covered withanother glass plate and irradiated with light (1.6 mW/cm², 10 minutes)with a fluorescent lamp (lamda max: 420 nm) to polymerize theprepolymer. After polymerization, two glass plates were separated andsonicated in borate buffer (pH 7.4 to 7.6) to demold the polymer film.The film was sterilized at 121° C. for 30 minutes, thereby obtaining afilm sample. The transparencies of the film samples are shown in Table3.

7. Examples B2 TO B6

The same operations as in Example B1 were repeated except that thesolvent of polymerization was changed as shown in Table 3. Thetransparency of the polymerization mixture and that of the film samplewere shown in Table 3.

8. Comparative Examples B1 TO B4

The same operations as in Example B1 were repeated except that thesolvent of the polymerization mixture was changed as shown in Table 3.The transparency of the polymerization mixture and that of the filmsample were shown in Table 3.

TABLE 3 Polymerization Solvent (n + 1)/(2n + m) mixture Film sampleExample B1 Ethylene Glycol mono n-butyl ether 0.333 Clear solutiontransparent Example B2 Ethylene Glycol mono n-hexyl ether 0.250 Clearsolution transparent Example B3 Diethylene Glycol mono n-butyl ether0.375 Clear solution transparent Example B4 Diethylene Glycol monon-hexyl 0.300 Clear solution transparent ether Example B5 TriethyleneGlycol mono n-butyl 0.400 Clear solution transparent ether Example B6Triethylene Glycol mono i-propyl 0.444 Clear solution transparent etherComparative Ethylene Glycol mono ethyl ether 0.500 Phase separation notExample B1 transparent Comparative Diethylene Glycol mono ethyl ether0.500 Phase separation not Example B2 transparent ComparativeTriethylene Glycol mono methyl 0.571 Phase separation not Example B3ether transparent Comparative Triethylene Glycol mono ethyl ether 0.500Phase separation not Example B4 transparent

9. Synthesis of Silicone Prepolymer B2 TO B7

The same operations as in Example B1 were repeated except that thecomposition of the polymerization mixture was changed as shown in Table4. The transparency of the polymerization mixture and that of the filmsample were shown in Table 3.

TABLE 4 Prepolymer Prepolymer Prepolymer Prepolymer PrepolymerPrepolymer Prepolymer B1 B2 B3 B4 B5 B6 B7 SiMAA 100.32 — 44.99 — —25.91 25.91 OH-mPDMS 108 65.52 62.25 60.25 — — mPDMS — — 22.36 5.26 8.2634.42 34.42 DMA 46.44 23.69 20.56 17.58 17.58 29.99 24.66 HEMA 18.368.58 9.87 9.75 11.75 6.62 10.95 ADVN 0.279 0.1 0.1 0.097 0.1 0.101 0.1DSH 2.232 0.4 0.8 0.776 0.8 0.808 0.8 UV absorber 6.12 2.19 2.19 2.192.19 2.19 2.19 Dye 0.0612 0.022 0.022 0.022 0.022 0.022 0.022 TAA 279.24100 100 97 100.1 101 100 unfunctionalized 65 80 80 80 80 80 80 polymerBHT 0.01 0.0124 0.0124 0.0124 0.0124 0.0124 0.0124 MOI 1.733 2.132 2.1322.132 2.132 2.132 2.132 DBTDL 30 37 37 37 37 37 37 Si content 16.0 15.016.0 16.4 16.4 15.8 16.0 PSRC* 75 66 45 64 60 26 26 *PolarSilicone-containing Residue Content of a prepolymer (by weight). PSRC iscalculated as (the weight of polar silicone-containing monomer)/(totalweight of the prepolymer) × 100.

10. Example B7 TO B10

The same operations as in Example B1 were repeated except that thesolvent of the polymerization mixture was changed as shown in Table 5.The transparency of the polymerization mixture and that of the filmsample were shown in Table 5.

11. Comparative Example B5 AND B6

The same operations as in Example B1 were repeated except that thesolvent of the polymerization mixture was changed as shown in Table 5.The transparency of the polymerization mixture and that of the filmsample were shown in Table 5.

TABLE 5 Transparency Diethylene glycol Triethylene glycol mono n-butylether mono n-butyl ether Polymerization Polymerization Prepolymermixture Film sample mixture Film sample Example B7 Prepolymer Clearsolution transparent Clear solution transparent B2 Example B8 PrepolymerClear solution transparent Clear solution transparent B3 Example B9Prepolymer Clear solution transparent Clear solution transparent B4Example Prepolymer Clear solution transparent Clear solution transparentB10 B5 Comparative Prepolymer Phase separation Not transparent Phaseseparation not transparent Example B5 B6 Comparative Prepolymer Phaseseparation Not transparent Phase separation not transparent Example B6B7

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the scope or spirit of the invention. Otherembodiments of the invention will be apparent to those skilled in theart from consideration of the specification and practice of theinvention disclosed herein. It is intended that the specification andexamples be considered as exemplary only, with a true scope and spiritof the invention being indicated by the following claims.

1. A composition comprising: a) from about 20% to about 95% content byweight of the composition of a silicone prepolymer having an averagesilicon content of from about 10% to about 30% by weight of theprepolymer, and b) from about 5% to about 80% content by weight of thecomposition of a solvent having a structure represented by formula (1s):R¹¹—O-G-R¹³,  (1s) wherein R¹¹ and R¹³ independently represent hydrogenor an organic radical comprising from 1 to 20 carbon atoms; and whereinG comprises: (1) at least one group having a structure represented byformula (1s1):

wherein the total number of group(s) in G having a structure representedby formula (1s1) is defined as m, and wherein m is an integer of from 1to 50; and (2) at least one group having a structure represented byformula (1s2):

wherein the total number of group(s) in G having a structure representedby formula (1s2) is defined as n, and wherein n is an integer of from 1to 50, and wherein R¹² is a divalent organic radical comprising from 3to 20 carbon atoms; and wherein m/(m+n) is from about 0.05 to about0.95; and c) wherein the composition further comprises from about 1% toabout 20% content by weight of the composition of poly(vinylpyrolidone).
 2. The composition of claim 1, further comprising aninitiator.
 3. The composition of claim 1, wherein R¹¹ and R¹³independently represent hydrogen, a C₁-C₂₀ alkyl residue, or a C₁-C₂₀aryl residue.
 4. The composition of claim 1, wherein R¹² represents aC₃-C₂₀ alkylene residue or a C₃-C₂₀ arylene residue.
 5. The compositionof claim 1, wherein (the number of oxygen atom)/(the number of carbonatom) in the formula (1s) is not more than 0.37.
 6. The composition ofclaim 1, wherein R¹² has a structure represented by formula (1s2-1):

wherein R¹⁴ represents a C₁-C₁₈ alkyl residue or a C₁-C₁₈ aryl residue.7. The composition of claim 1, wherein the number average molecularweight of the solvent is not more than
 450. 8. The composition of claim1, wherein one of R¹¹ and R¹³ represents hydrogen and the other of R¹¹and R¹³ represents a C₁-C₁₀ alkyl residue or a C₁-C₁₀ aryl residue. 9.The composition of claim 1, wherein m/(m+n) is from about 0.2 to about0.8.
 10. The composition of claim 1, wherein ethylene oxide residue(s)and —R¹²—O— group(s) in the solvent represented by the formula (s) arerandomly copolymerized.
 11. The composition of claim 1, wherein thesilicone prepolymer comprises: a) at least one silicone-containingresidue having a structure represented by the formula (a):

wherein R_(a) represents hydrogen or methyl, and wherein A represents asiloxanyl group; and b) at least one polymerizable residue having astructure represented by the formula (p):

wherein R_(p) represents hydrogen or methyl, and wherein P represents anorganic group comprising at least one polymerizable moiety; wherein atleast one of the at least one silicone-containing residue is a polarsilicone-containing residue further comprising at least one polarmoiety; and wherein the prepolymer has a polar silicone-containingresidue content of from about 30% to about 90% by weight of theprepolymer.
 12. The composition of claim 11, wherein the siliconeprepolymer further comprises at least one hydrophilic residue having astructure represented by the following formula (b):

wherein R_(b) represents hydrogen or methyl; and wherein B represents ahydrophilic group.
 13. A method for producing a polymer comprising thestep of polymerizing prepolymer from the composition of claim 1, therebyproviding the polymer.
 14. The polymer produced by the process of claim13.
 15. An ophthalmic lens comprising the polymer of claim
 14. 16. Acontact lens comprising the polymer of claim
 14. 17. A compositioncomprising: a) from about 20% to about 95% content by weight of thecomposition of a silicone prepolymer having an average silicon contentof from about 10% to about 30% by weight of the prepolymer, and b) fromabout 5% to about 80% content by weight of the composition of a solventhaving a structure represented by formula (2s):

wherein R²¹ to R²⁴ independently represent hydrogen or an organicradical comprising from 1 to 20 carbon atoms; wherein R²⁵ and R²⁶independently represent hydrogen or an organic radical comprising from 1to 20 carbon atoms; wherein n represent integers of from 1 to 50;wherein the total number of carbon atom in R²⁵ and R²⁶ is defined as r;and wherein (n+1)/(2n+r) is not more than about 0.45; and c) wherein thecomposition further comprises from about 1% to about 20% content byweight of the composition of poly(vinyl pyrolidone).
 18. The compositionof claim 17, further comprising an initiator.
 19. The composition ofclaim 17, wherein R²¹ to R²⁴ independently represent hydrogen, a C₁-C₂₀alkyl residue, or a C₁-C₂₀ aryl residue or wherein two or more of R²¹ toR²⁴ together form a ring structure.
 20. The composition of claim 17,wherein R²⁵ and R²⁶ independently represent hydrogen or a C₁-C₂₀ alkylresidue or a C₁-C₂₀ aryl residue.
 21. The composition of claim 17,wherein all of R²¹ to R²⁴ represent hydrogen.
 22. The composition ofclaim 17, wherein one of R²⁵ and R²⁶ represents hydrogen, and the otherof R²⁵ and R²⁶ represents a C₃ or higher alkyl residue or C₃ or higheraromatic residue.
 23. The composition of claim 17, wherein (n+1)/(2n+r)is not more than 0.40.
 24. The composition of claim 17, wherein thenumber average molecular weight of the solvent is not more than
 450. 25.The composition of claim 17, wherein the silicone prepolymer comprises:a) at least one silicone-containing residue having a structurerepresented by the formula (a):

wherein R_(a) represents hydrogen or methyl, and wherein A represents asiloxanyl group; and b) at least one polymerizable residue having astructure represented by the formula (p):

wherein R_(p) represents hydrogen or methyl, and wherein P represents anorganic group comprising at least one polymerizable moiety; wherein atleast one of the at least one silicone-containing residue is a polarsilicone-containing residue further comprising at least one polarmoiety; and wherein the prepolymer has a polar silicone-containingresidue content of from about 30% to about 90% by weight of theprepolymer.
 26. The composition of claim 25, wherein the siliconeprepolymer further comprises at least one hydrophilic residue having astructure represented by the following formula (b):

wherein R_(b) represents hydrogen or methyl; and wherein B represents ahydrophilic group.
 27. A method for producing a polymer comprising thestep of polymerizing prepolymer from the composition of claim 17,thereby providing the polymer.
 28. The polymer produced by the processof claim
 27. 29. An ophthalmic lens comprising the polymer of claim 28.30. A contact lens comprising the polymer of claim 28.